• tools and basic grammar
  • from rgb
  • from 256 colors
  • from hex
• ansi colors
  • xterm color code
  • RGB colors
  • tools
  • 256 color table
• color names
  • xterm 256 colors chart
  • 256 colors cheat sheet
• man page colors
  • settings
  • using vim as man pager
  • ansicolor issues in man page
• others
  • grep colors
  • generate color randomly
  • decolorize

[!TIP]

• * iMarslo : git config colors

• foreground colors

  ┏━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━┓
  ┃ ### ┃ GNOME TERMINAL          ┃ XTERM                   ┃ NON-GUI TTY           ┃
  ┡━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━┩
  │  39 │ «reset this color»      │ «reset this color»      │ «reset this color»    │
  ├─────┼─────────────────────────┼─────────────────────────┼───────────────────────┤
  │  30 │ very dark grey          │ black                   │ black                 │
  │  31 │ dull red                │ red                     │ light red             │
  │  32 │ dull green              │ light green             │ light green           │
  │  33 │ dull yellow             │ yellow                  │ yellow                │
  │  34 │ greyish blue            │ dark blue               │ sky blue              │
  │  35 │ dull purple             │ purple                  │ purple                │
  │  36 │ teal                    │ cyan                    │ cyan                  │
  │  37 │ light grey              │ light grey              │ light grey            │
  ├─────┼─────────────────────────┼─────────────────────────┼───────────────────────┤
  │  90 │ dark grey               │ dull grey               │ dull grey             │
  │  91 │ red                     │ bright red              │ bright red            │
  │  92 │ lime green              │ bright green            │ bright green          │
  │  93 │ yellow                  │ bright yellow           │ pure yellow           │
  │  94 │ light greyish blue      │ dull blue               │ deep blue             │
  │  95 │ light purple            │ magenta                 │ magenta               │
  │  96 │ cyan                    │ bright cyan             │ bright cyan           │
  │  97 │ off white               │ white                   │ white                 │
  ├─────┴──────┬──────────────────┴─────────────────────────┴───────────────────────┤
  │ 38;2;ʀ;ɢ;ʙ │ replace ʀ, ɢ, and ʙ with RGB values from 0 to 255                  │
  │            │   for closest supported color (non-GUI TTY has only 16 colors!)    │
  │ 38;5;ɴ     │ replace ɴ with value from 256-color chart below                    │
  │            │   for closest supported color (non-GUI TTY has only 16 colors!)    │
  └────────────┴────────────────────────────────────────────────────────────────────┘
  

• background colors

  ┏━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━┓
  ┃ ### ┃ GNOME TERMINAL          ┃ XTERM                   ┃ NON-GUI TTY           ┃
  ┡━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━┩
  │  49 │ «reset this color»      │ «reset this color»      │ «reset this color»    │
  ├─────┼─────────────────────────┼─────────────────────────┼───────────────────────┤
  │  40 │ very dark grey          │ black                   │ black                 │
  │  41 │ dull red                │ red                     │ light red             │
  │  42 │ dull green              │ light green             │ light green           │
  │  43 │ dull yellow             │ yellow                  │ yellow                │
  │  44 │ greyish blue            │ dark blue               │ sky blue              │
  │  45 │ dull purple             │ purple                  │ purple                │
  │  46 │ teal                    │ cyan                    │ cyan                  │
  │  47 │ light grey              │ light grey              │ light grey            │
  ├─────┼─────────────────────────┼─────────────────────────┼╶╴╶╴╶╴╶╴╶╴╶╴╶╴╶╴╶╴╶╴╶╴╶┤
  │ 100 │ dark grey               │ dull grey               │ black                 │
  │ 101 │ red                     │ bright red              │ light red             │
  │ 102 │ lime green              │ bright green            │ light green           │
  │ 103 │ yellow                  │ bright yellow           │ yellow                │
  │ 104 │ light greyish blue      │ dull blue               │ sky blue              │
  │ 105 │ light purple            │ magenta                 │ purple                │
  │ 106 │ cyan                    │ bright cyan             │ cyan                  │
  │ 107 │ off white               │ white                   │ light grey            │
  ├─────┴──────┬──────────────────┴─────────────────────────┴───────────────────────┤
  │ 48;2;ʀ;ɢ;ʙ │ replace ʀ, ɢ, and ʙ with RGB values from 0 to 255                  │
  │            │   for closest supported color (non-GUI TTY has only 8 colors!)     │
  │ 48;5;ɴ     │ replace ɴ with value from 256-color chart below                    │
  │            │   for closest supported color (non-GUI TTY has only 8 colors!)     │
  └────────────┴────────────────────────────────────────────────────────────────────┘
  

• text styling

  ┏━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━┓
  ┃ ### ┃ GNOME TERMINAL          ┃ XTERM                   ┃ NON-GUI TTY           ┃
  ┡━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━┩
  │     │ «reset style+colors»    │ «reset style+colors»    │ «reset style+colors»  │
  │   0 │ «reset style+colors»    │ «reset style+colors»    │ «reset style+colors»  │
  ├─────┼─────────────────────────┼─────────────────────────┼───────────────────────┤
  │   1 │ +bold, +brighter color  │ +bold, +brighter color  │ +brighter color,      │
  │     │                         │                         │   -forced grey        │
  │   2 │ +fainter color          │ +fainter color          │ +forced grey          │
  │   3 │ +italic                 │ +italic                 │ +forced green         │
  │     │                         │                         │   ● overrides 2 and 4 │
  │   4 │ +underline              │ +underline              │ +forced cyan          │
  │     │                         │                         │   ● overrides 2       │
  │   5 │ «no effect»             │ +blink                  │ «no effect»           │
  │   7 │ +invert colors          │ +invert colors          │ +invert colors        │
  │   8 │ +invisible              │ +invisible              │ «no effect»           │
  │     │                         │   ● underline appears   │                       │
  │   9 │ +strikethrough          │ +strikethrough          │ «no effect»           │
  ├─────┼─────────────────────────┤                         ├───────────────────────┤
  │  21 │ -bold, -brighter color, │ +double underline       │ -brighter color,      │
  │     │   -fainter color        ├─────────────────────────┤   -forced grey        │
  │  22 │ -bold, -brighter color, │ -bold, -brighter color, │ -brighter color,      │
  │     │   -fainter color        │   -fainter color        │   -forced grey        │
  │  23 │ -italic                 │ -italic                 │ -forced green         │
  │  24 │ -underline              │ -underline,             │ -forced cyan          │
  │     │                         │   -double underline     │                       │
  │  25 │ «no effect»             │ -blink                  │ «no effect»           │
  │  27 │ -invert colors          │ -invert colors          │ -invert colors        │
  │  28 │ -invisible              │ -invisible              │ «no effect»           │
  │  29 │ -strikethrough          │ -strikethrough          │ «no effect»           │
  └─────┴─────────────────────────┴─────────────────────────┴───────────────────────┘
  

• Font Effects

  ┏━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
  ┃   Code  ┃            Effect            ┃                            Note                                        ┃
  ┡━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
  │    0    │ Reset / Normal               │ all attributes off                                                     │
  │    1    │ Bold or increased intensity  │                                                                        │
  │    2    │ Faint (decreased intensity)  │ Not widely supported.                                                  │
  │    3    │ Italic                       │ Not widely supported. Sometimes treated as inverse.                    │
  │    4    │ Underline                    │                                                                        │
  │    5    │ Slow Blink                   │ less than 150 per minute                                               │
  │    6    │ Rapid Blink                  │ MS-DOS ANSI.SYS; 150+ per minute; not widely supported                 │
  │    7    │ [[reverse video]]            │ swap foreground and background colors                                  │
  │    8    │ Conceal                      │ Not widely supported.                                                  │
  │    9    │ Crossed-out                  │ Characters legible, but marked for deletion. Not widely supported.     │
  │    10   │ Primary(default) font        │                                                                        │
  │  11–19  │ Alternate font               │ Select alternate font n-10                                             │
  │    20   │ Fraktur                      │ hardly ever supported                                                  │
  │    21   │ Bold off or Double Underline │ Bold off not widely supported; double underline hardly ever supported. │
  │    22   │ Normal color or intensity    │ Neither bold nor faint                                                 │
  │    23   │ Not italic, not Fraktur      │                                                                        │
  │    24   │ Underline off                │ Not singly or doubly underlined                                        │
  │    25   │ Blink off                    │                                                                        │
  │    27   │ Inverse off                  │                                                                        │
  │    28   │ Reveal                       │ conceal off                                                            │
  │    29   │ Not crossed out              │                                                                        │
  │  30–37  │ Set foreground color         │ See color table below                                                  │
  │    38   │ Set foreground color         │ Next arguments are 5;<n> or 2;<r>;<g>;<b>, see below                   │
  │    39   │ Default foreground color     │ implementation defined (according to standard)                         │
  │  40–47  │ Set background color         │ See color table below                                                  │
  │    48   │ Set background color         │ Next arguments are 5;<n> or 2;<r>;<g>;<b>, see below                   │
  │    49   │ Default background color     │ implementation defined (according to standard)                         │
  │    51   │ Framed                       │                                                                        │
  │    52   │ Encircled                    │                                                                        │
  │    53   │ Overlined                    │                                                                        │
  │    54   │ Not framed or encircled      │                                                                        │
  │    55   │ Not overlined                │                                                                        │
  │    60   │ ideogram underline           │ hardly ever supported                                                  │
  │    61   │ ideogram double underline    │ hardly ever supported                                                  │
  │    62   │ ideogram overline            │ hardly ever supported                                                  │
  │    63   │ ideogram double overline     │ hardly ever supported                                                  │
  │    64   │ ideogram stress marking      │ hardly ever supported                                                  │
  │    65   │ ideogram attributes off      │ reset the effects of all of 60-64                                      │
  │  90–97  │ Set bright foreground color  │ aixterm (not in standard)                                              │
  │ 100–107 │ Set bright background color  │                                                                        │
  └─────────┴──────────────────────────────┴────────────────────────────────────────────────────────────────────────┘
  

• quick show colors:

  $ for i in {0..255}; do echo -e "\033[38;5;${i}m $i \033[0m"; done
  

tools and basic grammar

[!NOTE|label:references:]

• termstandard/colors
• ANSI escape code
• * iMarslo: icolor.sh
• * iMarslo: marslo/color-utils.sh
• * fromhex() & tohex()

• escape sequence

• normal & bright

  $ for (( i = 30; i < 38; i++ )); do
    echo -e "\033[0;"$i"m Normal: (0;$i); \033[1;"$i"m Light: (1;$i)";
  done
  

  

from rgb

[!NOTE|label:references:]

• rgbToAnsi256(r, g, b)

• rgb to hex

  # @author : Anthony Bourdain | https://stackoverflow.com/a/55073732/2940319
  # @usage  :
  # - `rgbtohex 17 0 26` ==> 1001A
  # - `rgbtohex -h 17 0 26` ==> #1001A
  function rgbtohex () {
    addleadingzero () { awk '{if(length($0)<2){printf "0";} print $0;}';}
    if [[ ${1} == "-h" ]]; then
      r=${2}; g=${3}; b=${4};h='#';
    else
      r=${1}; g=${2}; b=${3};h='';
    fi
    r=$(echo "obase=16; ${r}" | bc | addleadingzero)
    g=$(echo "obase=16; ${g}" | bc | addleadingzero)
    b=$(echo "obase=16; ${b}" | bc | addleadingzero)
    echo "${h}${r}${g}${b}"
  }
  

• rgb to 256colors

  # @author : Anthony Bourdain | https://stackoverflow.com/a/55073732/2940319
  # @usage  :
  # - `rgbto256 0 95, 135` ==> 22
  function rgbto256 () {
    echo "define trunc(x){auto os;os=scale;scale=0;x/=1;scale=os;return x;};" \
      "16 + 36 * trunc(${1}/51) + 6 * trunc(${2}/51) +" \
      " trunc(${3}/51)" | bc
    # XTerm Color Number = 16 + 36 * R + 6 * G + B | 0 <= R,G,B <= 5
  }
  

• rgb to hsv

from 256 colors

• xColorTable | original

  $ xColorTable 30 45 100
  30  = rgb(0, 135, 135)   => #008787
  45  = rgb(0, 215, 255)   => #00D7FF
  100 = rgb(135, 135, 0)   => #878700
  

  

• 256color to hex

  tohex(){
    dec=$(($1%256))   ### input must be a number in range 0-255.
    if [ "$dec" -lt "16" ]; then
      bas=$(( dec%16 ))
      mul=128
      [ "$bas" -eq "7" ] && mul=192
      [ "$bas" -eq "8" ] && bas=7
      [ "$bas" -gt "8" ] && mul=255
      a="$((  (bas&1)    *mul ))"
      b="$(( ((bas&2)>>1)*mul ))"
      c="$(( ((bas&4)>>2)*mul ))"
      printf 'dec= %3s basic= #%02x%02x%02x\n' "$dec" "$a" "$b" "$c"
    elif [ "$dec" -gt 15 ] && [ "$dec" -lt 232 ]; then
      b=$(( (dec-16)%6  )); b=$(( b==0?0: b*40 + 55 ))
      g=$(( (dec-16)/6%6)); g=$(( g==0?0: g*40 + 55 ))
      r=$(( (dec-16)/36 )); r=$(( r==0?0: r*40 + 55 ))
      printf 'dec= %3s color= #%02x%02x%02x\n' "$dec" "$r" "$g" "$b"
    else
      gray=$(( (dec-232)*10+8 ))
      printf 'dec= %3s  gray= #%02x%02x%02x\n' "$dec" "$gray" "$gray" "$gray"
    fi
  }
  
  for i in $(seq 0 255); do
      tohex ${i}
  done
  

from hex

• hex to 256colors

  fromhex(){
    hex=${1#"#"}
    r=$(printf '0x%0.2s' "$hex")
    g=$(printf '0x%0.2s' ${hex#??})
    b=$(printf '0x%0.2s' ${hex#????})
    printf '%03d' "$(( (r<75?0:(r-35)/40)*6*6 +
                       (g<75?0:(g-35)/40)*6   +
                       (b<75?0:(b-35)/40)     + 16 ))"
  }
  
  # verify
  $ xColorTable 30
  30  = rgb(0, 135, 135)   => #008787
  
  $ fromhex 008787
  030
  $ fromhex 008766
  029
  $ fromhex 008788
  030
  

• hex to rgb

  # @author : Anthony Bourdain | https://stackoverflow.com/a/55073732/2940319
  # @usage  :
  # - `hexttorgb "11001A" ==> 17 0 26
  # - `hexttorgb "#11001A" ==> 17 0 26
  function hextorgb () {
    hexinput=$(echo "${1}" | tr '[:lower:]' '[:upper:]')           # uppercase-ing
    hexinput=$(echo "${hexinput}" | tr -d '#')                     # remove Hash if needed
    a=$(echo "${hexinput}" | cut -c-2)
    b=$(echo "${hexinput}" | cut -c3-4)
    c=$(echo "${hexinput}" | cut -c5-6)
    r=$(echo "ibase=16; ${a}" | bc)
    g=$(echo "ibase=16; ${b}" | bc)
    b=$(echo "ibase=16; ${c}" | bc)
    echo "${r} ${g} ${b}"
  }
  

ansi colors

[!NOTE|label:references:]

• How to have multiple colors in a Windows batch file?
• How to get the RGB values of a 256-color palette terminal color
• kenny-kvibe/ansi_colors.sh
• * iMarslo: icolor.sh

xterm color code

• echo

  #                 0 - 255
  #                    v
  $ echo -e "\033[38;5;3mhello world\033[0m"
  
  # for all
  $ for i in {0..255}; do echo -e "\033[38;5;${i}m $i \033[0m"; done
  

• printf

  #         ╭─ \b      Write a <backspace> character.
  #         ╷            0 - 255
  #         v               v
  $ printf "%-10b" "\e[38;5;3m**text**\e[0m"
  
  # or ignore `%b`
  $ printf "\e[38;5;3m**text**\e[0m"
  

• tput

  [!NOTE|label:references::]

  • * iMarslo: linux/nutshell
  • * 256 colors
  • Colours and Cursor Movement With tput
  • tput: Portable Terminal Control
  • use cases:
    • * iMarslo: fman()
    • * iMarslo: PS1

  #          0 - 255                       reset
  #            v                             v
  $ tput setaf 30; echo "hello world"; tput sgr0
  # or
  $ echo -e "$(tput setaf 30)hello world$(tput sgr0)"
  
  # more
  $ tput setaf 30 | command cat -A
  ^[[38;5;30m
  

  • background color

    $ echo $(tput setab 214)256 $(tput setab 202)colors
    

  • to show color table

    $ for c in {0..255}; do tput setaf $c; tput setaf $c | command cat -v; echo =$c; done
    

  • show current terminal support

    $ tput colors
    256
    

RGB colors

[!NOTE|label:references:]

• * iMarslo : git » config » colors
• * iMarslo: math » number conversion » to decimal

• echo

  # #689d6a
  #                       ╭─ R(decimal)         : 104 : `$ echo -n "obase=10;ibase=16; 68" | bc`
  #                       ╷   ╭─ G(decimal)     : 157 : `$ echo -n "obase=10;ibase=16; 9D" | bc`
  #                       ╷   ╷   ╭─ B(decimal) : 106 : `$ echo -n "obase=10;ibase=16; 6A" | bc`
  #                      --- --- ---
  $ echo -e '\x1b[3;38;2;104;157;106m hello world \x1b[m'
  #               -      --- --- ---
  #               ╵      68  9D  6A
  #               ╰─ SGR (Select Graphic Rendition) parameters ( https://en.wikipedia.org/wiki/ANSI_escape_code ):
  #                      0 reset/normal ; 1 bold      ; 2 dim/faint ;
  #                      3 italic       ; 4 underline ; 5 blink     ;
  #                      7 reverse      ; 8 hidden
  
  # or
  $ echo $(git config --get-color "" "#689d6a italic") color test $(git config --get-color "" reset) | command cat -A
  ^[[3;38;2;104;157;106m color test ^[[m$
  #         --- --- ---
  #         68  9D  6A   : hex
  #         104 157 106  : decimal
  

• printf

  $ hextorgb '#6A5ACD'
  106 90 205
  
  #                        6A  5A CD
  #                        --- -- ---
  $ printf "%b" '\x1b[38;2;106;90;205m-hello world-\x1b[0m'
  
  # omit %b
  $ printf '\x1b[38;2;106;90;205m-hello world-\x1b[0m'
  

• for PS1

  [!NOTE|label:references:]

  • Using ANSI Color Codes to Colorize Your Bash Prompt on Linux

  # additioanl \[ and \] for PS1 only
  #  ^                     ^
  #  --                    --
  R='\[\e[38;2;255;100;100m\]'
  G='\[\e[38;2;100;255;100m\]'
  B='\[\e[38;2;100;100;255m\]'
  W='\[\e[0m\]'
  PS1="[$R\u$W@$B\h$W:$G\w$W]\$ "
  

• RGB for both foreground and background

  # 38;2;R;G;B
  # 48;2;R;G;B
  $ echo -e "\033[38;2;255;100;100mhello world\033[0m"
  $ echo -e "\033[48;2;255;100;100mhello world\033[0m"
  
  #                 38;2;R;G;B     48;2;R;G;B
  #               v------------v v-------------v
  $ echo -e "\033[38;2;155;106;0;48;2;255;100;100mhello world\033[0m"
  
  # https://web.archive.org/web/20131009193526/http://bitmote.com/index.php?post/2012/11/19/Using-ANSI-Color-Codes-to-Colorize-Your-Bash-Prompt-on-Linux
  $ echo -e "testing \033[38;5;196;48;5;21mCOLOR1\033[38;5;208;48;5;159mCOLOR2\033[m"
  

tools

• fidian/ansi

  # install
  $ [[ ! -f /opt/ansi ]] && curl -sL git.io/ansi -o /opt/ansi
  $ chmod +x /opt/ansi
  $ ln -sf /opt/ansi /usr/local/bin/ansi
  
  # usage
  $ ansi --color-table
  $ ansi --color-codes
  

  

• bash-colors c()

  # install
  $ curl -o /opt/bash-colors.sh -fsSL https://github.com/ppo/bash-colors/blob/master/bash-colors.sh
  $ echo "[[ -f \"/opt/bash-colors.sh\" ]] && source \"/opt/bash-colors.sh\" >> ~/.bashrc"
  
  # or using source code directly
  # shellcheck disable=SC2015,SC2059
  c() { [ $# == 0 ] && printf "\e[0m" || printf "$1" | sed 's/\(.\)/\1;/g;s/\([SDIUFNHT]\)/2\1/g;s/\([KRGYBMCW]\)/3\1/g;s/\([krgybmcw]\)/4\1/g;y/SDIUFNHTsdiufnhtKRGYBMCWkrgybmcw/12345789123457890123456701234567/;s/^\(.*\);$/\\e[\1m/g'; }
  # shellcheck disable=SC2086
  cecho() { echo -e "$(c $1)${2}\e[0m"; }
  
  # sample
  $ echo -e "$(c Gs)bold green$(c) and $(c i)Italic$(c) and normal"
  

  

• say()

  say() {
   echo "$@" | sed \
         -e "s/\(\(@\(red\|green\|yellow\|blue\|magenta\|cyan\|white\|reset\|b\|u\)\)\+\)[[]\{2\}\(.*\)[]]\{2\}/\1\4@reset/g" \
         -e "s/@red/$(tput setaf 1)/g" \
         -e "s/@green/$(tput setaf 2)/g" \
         -e "s/@yellow/$(tput setaf 3)/g" \
         -e "s/@blue/$(tput setaf 4)/g" \
         -e "s/@magenta/$(tput setaf 5)/g" \
         -e "s/@cyan/$(tput setaf 6)/g" \
         -e "s/@white/$(tput setaf 7)/g" \
         -e "s/@reset/$(tput sgr0)/g" \
         -e "s/@b/$(tput bold)/g" \
         -e "s/@u/$(tput sgr 0 1)/g"
  }
  
  # example
  $ say @b@green[[Success]]
  $ say @b@yellowWARNING @red..message..
  

  

• RGBcolor

  function RGBcolor {
    echo "16 + $1 * 36 + $2 * 6 + $3" | bc
  }
  
  fg=$(RGBcolor 1 0 2)  # Violet
  bg=$(RGBcolor 5 3 0)  # Bright orange.
  
  echo -e "\\033[1;38;5;$fg;48;5;${bg}mviolet on tangerine\\033[0m"
  

• terminal-colors | eikenb/terminal-colors

  $ python3 -m pip install terminal-colors
  
  # usage
  $ terminal-colors -l
  $ terminal-colors -n
  $ terminal-colors -n -p
  

  

  

• colored

  # install
  $ python3 -m pip install colored
  
  # usage
  $ colored --help
  $ colored --color-codes
  

• topic: ansi-colors

  • trapd00r/colorcoke
  • shakibamoshiri/bline

256 color table

[!NOTE|label:references:]

• xterm 256color chart.svg
• color grid

• 256 colors

  function 256colors() {
    local bar='█'                                          # ctrl+v -> u2588 ( full block )
    if uname -r | grep -q "microsoft"; then bar='▌'; fi    # ctrl+v -> u258c ( left half block )
    for i in {0..255}; do
      echo -e "\e[38;05;${i}m${bar}${i}";
    done | column -c 180 -s ' ';
    echo -e "\e[m"
  }
  

  

  #!/bin/bash
  
  # This program is free software. It comes without any warranty, to
  # the extent permitted by applicable law. You can redistribute it
  # and/or modify it under the terms of the Do What The Fuck You Want
  # To Public License, Version 2, as published by Sam Hocevar. See
  # http://sam.zoy.org/wtfpl/COPYING for more details.
  
  for fgbg in 38 48 ; do # Foreground / Background
      for color in {0..255} ; do # Colors
          # Display the color
          printf "\e[${fgbg};5;%sm  %3s  \e[0m" $color $color
          # Display 6 colors per lines
          if [ $((($color + 1) % 6)) == 4 ] ; then
              echo # New line
          fi
      done
      echo # New line
  done
  exit 0
  

  

• colors and formatting

  reference:

  • 256-colors.sh

  #!/bin/sh
  
  # From: https://misc.flogisoft.com/bash/tip_colors_and_formatting#colors2
  # Modified by steve.tarver@gmail.com to work in Alpine Linux ash
  
  # This program is free software. It comes without any warranty, to
  # the extent permitted by applicable law. You can redistribute it
  # and/or modify it under the terms of the Do What The Fuck You Want
  # To Public License, Version 2, as published by Sam Hocevar. See
  # http://sam.zoy.org/wtfpl/COPYING for more details.
  
  for clbg in {40..47} {100..107} 49 ; do   # background
    for clfg in {30..37} {90..97} 39 ; do   # foreground
      for attr in 0 1 2 3 4 5 7 ; do        # formatting
        #Print the result
        echo -en "\e[${attr};${clbg};${clfg}m ^[${attr};${clbg};${clfg}m \e[0m"
      done
      echo                                  # newline
    done
  done
  exit 0
  

  

  for attr in 0 1 2 3 4 5 6 7; do
    echo "------------------------------------------------"
    printf "ESC[%s;Foreground;Background - \n" $attr
    for fore in 30 31 32 33 34 35 36 37; do
        for back in 40 41 42 43 44 45 46 47; do
            printf '\033[%s;%s;%sm %02s;%02s\033[0m' $attr $fore $back $fore $back
        done
    printf '\n'
    done
    printf '\033[0m'
  done
  

  

• showColors

  # @author : https://stackoverflow.com/a/69648792/2940319
  # @usage  :
  #   - `showcolors fg` : default
  #   - `showcolors bg`
  # @alternative: `ansi --color-codes`
  function showcolors() {
    local row col blockrow blockcol red green blue
    local showcolor=_showcolor_${1:-fg}
    local white="\033[1;37m"
    local reset="\033[0m"
  
    echo -e "set foreground color: \\\\033[38;5;${white}NNN${reset}m"
    echo -e "set background color: \\\\033[48;5;${white}NNN${reset}m"
    echo -e "reset color & style:  \\\\033[0m"
    echo
  
    echo 16 standard color codes:
    for row in {0..1}; do
      for col in {0..7}; do
        $showcolor $(( row*8 + col )) "${row}"
      done
      echo
    done
    echo
  
    echo 6·6·6 RGB color codes:
    for blockrow in {0..2}; do
      for red in {0..5}; do
        for blockcol in {0..1}; do
          green=$(( blockrow*2 + blockcol ))
          for blue in {0..5}; do
            $showcolor $(( red*36 + green*6 + blue + 16 )) $green
          done
          echo -n "  "
        done
        echo
      done
      echo
    done
  
    echo 24 grayscale color codes:
    for row in {0..1}; do
      for col in {0..11}; do
        $showcolor $(( row*12 + col + 232 )) "${row}"
      done
      echo
    done
    echo
  }
  
  function _showcolor_fg() {
    # shellcheck disable=SC2155
    local code=$( printf %03d "$1" )
    echo -ne "\033[38;5;${code}m"
    echo -nE " $code "
    echo -ne "\033[0m"
  }
  
  function _showcolor_bg() {
    if (( $2 % 2 == 0 )); then
      echo -ne "\033[1;37m"
    else
      echo -ne "\033[0;30m"
    fi
    # shellcheck disable=SC2155
    local code=$( printf %03d "$1" )
    echo -ne "\033[48;5;${code}m"
    echo -nE " $code "
    echo -ne "\033[0m"
  }
  

  

• colorgrid

  function colorgrid() {
      iter=16
      while [ $iter -lt 52 ]
      do
          second=$[$iter+36]
          third=$[$second+36]
          four=$[$third+36]
          five=$[$four+36]
          six=$[$five+36]
          seven=$[$six+36]
          if [ $seven -gt 250 ];then seven=$[$seven-251]; fi
  
          echo -en "\033[38;5;$(echo $iter)m█ "
          printf "%03d" $iter
          echo -en "   \033[38;5;$(echo $second)m█ "
          printf "%03d" $second
          echo -en "   \033[38;5;$(echo $third)m█ "
          printf "%03d" $third
          echo -en "   \033[38;5;$(echo $four)m█ "
          printf "%03d" $four
          echo -en "   \033[38;5;$(echo $five)m█ "
          printf "%03d" $five
          echo -en "   \033[38;5;$(echo $six)m█ "
          printf "%03d" $six
          echo -en "   \033[38;5;$(echo $seven)m█ "
          printf "%03d" $seven
  
          iter=$[$iter+1]
          printf '\r\n'
      done
  }
  

• solarized color

  #!/bin/bash
  
  # solarized ansicolors (exporting for grins)
  export base03='\033[0;30;40m'
  export base02='\033[1;30;40m'
  export base01='\033[0;32;40m'
  export base00='\033[0;33;40m'
  export base0='\033[0;34;40m'
  export base1='\033[0;36;40m'
  export base2='\033[0;37;40m'
  export base3='\033[1;37;40m'
  export yellow='\033[1;33;40m'
  export orange='\033[0;31;40m'
  export red='\033[1;31;40m'
  export magenta='\033[1;35;40m'
  export violet='\033[0;35;40m'
  export blue='\033[1;34;40m'
  export cyan='\033[1;36;40m'
  export green='\033[1;32;40m'
  export reset='\033[0m'
  
  colors () {
    echo -e "base03  ${base03}Test$reset"
    echo -e "base02  ${base02}Test$reset"
    echo -e "base01  ${base01}Test$reset"
    echo -e "base00  ${base00}Test$reset"
    echo -e "base0   ${base0}Test$reset"
    echo -e "base1   ${base1}Test$reset"
    echo -e "base2   ${base2}Test$reset"
    echo -e "base3   ${base3}Test$reset"
    echo -e "yellow  ${yellow}Test$reset"
    echo -e "orange  ${orange}Test$reset"
    echo -e "red     ${red}Test$reset"
    echo -e "magenta ${magenta}Test$reset"
    echo -e "violet  ${violet}Test$reset"
    echo -e "blue    ${blue}Test$reset"
    echo -e "cyan    ${cyan}Test$reset"
    echo -e "green   ${green}Test$reset"
  }
  colors
  

  

color names

[!TIP|label:references:]

• Web colors
• The 256 color table and its partitioning

• blue

  

• brown

  

• cyan

  

• gray.black

  

• green

  

• orange

  

• pink

  

• purple.magenta

  

• red

  

• white

  

• yellow

  

xterm 256 colors chart

[!NOTE|label:references:]

• * Color names
• * Web colors

256 colors cheat sheet

man page colors

settings

• printf

  # The color of man page
  export LESS_TERMCAP_mb=$(printf "\\e[1;31m")         # begin blinding
  export LESS_TERMCAP_md=$(printf "\\e[1;31m")         # begin bold
  export LESS_TERMCAP_me=$(printf "\\e[0m")            # end mode
  export LESS_TERMCAP_se=$(printf "\\e[0m")            # end stadout-mode
  export LESS_TERMCAP_so=$(printf "\\e[1;44;33m")      # begin stadout-mode - info box
  export LESS_TERMCAP_so=$(printf "\\e[1;33m")      # begin stadout-mode - info box
  export LESS_TERMCAP_ue=$(printf "\\e[0m")            # end underline
  export LESS_TERMCAP_us=$(printf "\\e[1;32m")         # begin underline
  export GROFF_NO_SGR=1         # For Konsole and Gnome-terminal
  export LESS='-eirMXR'
  export SYSTEMD_LESS=FRXMK
  export MANPAGER='less -s -M +Gg'
  

• tput

  export LESS_TERMCAP_mb=$(tput bold; tput setaf 2) # green
  export LESS_TERMCAP_md=$(tput bold; tput setaf 6) # cyan
  export LESS_TERMCAP_me=$(tput sgr0)
  export LESS_TERMCAP_so=$(tput bold; tput setaf 3; tput setab 4) # yellow on blue
  export LESS_TERMCAP_se=$(tput rmso; tput sgr0)
  export LESS_TERMCAP_us=$(tput smul; tput bold; tput setaf 7) # white
  export LESS_TERMCAP_ue=$(tput rmul; tput sgr0)
  export LESS_TERMCAP_mr=$(tput rev)
  export LESS_TERMCAP_mh=$(tput dim)
  export LESS_TERMCAP_ZN=$(tput ssubm)
  export LESS_TERMCAP_ZV=$(tput rsubm)
  export LESS_TERMCAP_ZO=$(tput ssupm)
  export LESS_TERMCAP_ZW=$(tput rsupm)
  export GROFF_NO_SGR=1         # For Konsole and Gnome-terminal
  

• $'\e'

  export LESS_TERMCAP_mb=$'\e[01;31m'       # begin blinking
  export LESS_TERMCAP_md=$'\e[01;37m'       # begin bold
  export LESS_TERMCAP_me=$'\e[0m'           # end all mode like so, us, mb, md, mr
  export LESS_TERMCAP_se=$'\e[0m'           # end standout-mode
  export LESS_TERMCAP_so=$'\e[45;93m'       # start standout mode
  export LESS_TERMCAP_ue=$'\e[0m'           # end underline
  export LESS_TERMCAP_us=$'\e[4;93m'        # start underlining
  

using vim as man pager

[!TIP]

• Using vim as a man-page viewer under Unix

export PAGER="/bin/sh -c \"unset PAGER;col -b -x | \
    vim -R -c 'set ft=man nomod nolist' -c 'map q :q<CR>' \
    -c 'map <SPACE> <C-D>' -c 'map b <C-U>' \
    -c 'nmap K :Man <C-R>=expand(\\\"<cword>\\\")<CR><CR>' -\""

ansicolor issues in man page

• error

  1mNAME0m       <-- BAD
         man - an interface to the on-line reference manuals
  
  1mSYNOPSIS0m   <-- BAD
         1mman  22m[1m-C  4m22mfile24m]  [1m-d22m]  [1m-D22m]  <-- BAD
  

• solution

  $ yum install man-pages man-db man
  
  # or
  $ sudo yum update man-pages man-db man
  

others

[!TIP]

• The 5 Best Color Picker Apps for Mac

grep colors

[!NOTE|label:grep_colors]

• Modifying the color of grep

$ export GREP_COLORS="ms=01;31;49:mc=01;31:sl=0;36:cx=:fn=35:ln=32:bn=32:se=36"
$ echo $GREP_COLORS
ms=01;31;49:mc=01;31:sl=0;36:cx=:fn=35:ln=32:bn=32:se=36

generate color randomly

$ echo "#$(openssl rand -hex 3)"
# or
$ hexdump -n 3 -v -e '"#" 3/1 "%02X" "\n"' /dev/urandom

# sample
$ echo -e "$(trueHexPrint $(echo "#$(openssl rand -hex 3)"))aaa\x1b[0m"

decolorize

[!NOTE|label:decolorize]

• Removing colors from output

$ command | sed -r "s/\x1B\[(([0-9]+)(;[0-9]+)*)?[mGKHfJ]//g"
# or
$ command | sed -r "s/\x1B\[[0-9;]*[JKmsu]//g"

# alias
alias decolorize='sed -r "s/\x1B\[(([0-9]+)(;[0-9]+)*)?[mGKHfJ]//g"'