tput setaf color table? How to determine color codes?
The count of colors available to tput is given by tput colors.
To see the basic 8 colors (as used by setf in urxvt terminal and setaf in xterm terminal):
$ printf '\e[%sm▒' {30..37} 0; echo ### foreground
$ printf '\e[%sm ' {40..47} 0; echo ### background
And usually named as this:
Color #define Value RGB
black COLOR_BLACK 0 0, 0, 0
red COLOR_RED 1 max,0,0
green COLOR_GREEN 2 0,max,0
yellow COLOR_YELLOW 3 max,max,0
blue COLOR_BLUE 4 0,0,max
magenta COLOR_MAGENTA 5 max,0,max
cyan COLOR_CYAN 6 0,max,max
white COLOR_WHITE 7 max,max,max
To see the extended 256 colors (as used by setaf in urxvt):
$ printf '\e[48;5;%dm ' {0..255}; printf '\e[0m \n'
If you want numbers and an ordered output:
#!/bin/bash
color(){
for c; do
printf '\e[48;5;%dm%03d' $c $c
done
printf '\e[0m \n'
}
IFS=$' \t\n'
color {0..15}
for ((i=0;i<6;i++)); do
color $(seq $((i*36+16)) $((i*36+51)))
done
color {232..255}
The 16 million colors need quite a bit of code (some consoles can not show this).
The basics is:
fb=3;r=255;g=1;b=1;printf '\e[0;%s8;2;%s;%s;%sm▒▒▒ ' "$fb" "$r" "$g" "$b"
fb is front/back or 3/4.
A simple test of your console capacity to present so many colors is:
for r in {200..255..5}; do fb=4;g=1;b=1;printf '\e[0;%s8;2;%s;%s;%sm ' "$fb" "$r" "$g" "$b"; done; echo
It will present a red line with a very small change in tone from left to right. If that small change is visible, your console is capable of 16 million colors.
Each r, g, and b is a value from 0 to 255 for RGB (Red,Green,Blue).
If your console type support this, this code will create a color table:
mode2header(){
#### For 16 Million colors use \e[0;38;2;R;G;Bm each RGB is {0..255}
printf '\e[mR\n' # reset the colors.
printf '\n\e[m%59s\n' "Some samples of colors for r;g;b. Each one may be 000..255"
printf '\e[m%59s\n' "for the ansi option: \e[0;38;2;r;g;bm or \e[0;48;2;r;g;bm :"
}
mode2colors(){
# foreground or background (only 3 or 4 are accepted)
local fb="$1"
[[ $fb != 3 ]] && fb=4
local samples=(0 63 127 191 255)
for r in "${samples[@]}"; do
for g in "${samples[@]}"; do
for b in "${samples[@]}"; do
printf '\e[0;%s8;2;%s;%s;%sm%03d;%03d;%03d ' "$fb" "$r" "$g" "$b" "$r" "$g" "$b"
done; printf '\e[m\n'
done; printf '\e[m'
done; printf '\e[mReset\n'
}
mode2header
mode2colors 3
mode2colors 4
To convert an hex color value to a (nearest) 0-255 color index:
fromhex(){
hex=${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 ))"
}
Use it as:
$ fromhex 00fc7b
048
$ fromhex #00fc7b
048
To find the color number as used in HTML colors format:
#!/bin/dash
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
Use it as ("basic" is the first 16 colors, "color" is the main group, "gray" is the last gray colors):
$ tohex 125 ### A number in range 0-255
dec= 125 color= #af005f
$ tohex 6
dec= 6 basic= #008080
$ tohex 235
dec= 235 gray= #262626
The tput utility is using a 256-color lookup table to print 8-bit ANSI escape sequences (starting with Esc and [) which makes use of terminal capabilities, so these control sequences can be interpreted as colors. These are pre-defined set of 256 colors used commonly across graphic cards.
To print all 256 colors in the terminal, try the following one-liner:
for c in {0..255}; do tput setaf $c; tput setaf $c | cat -v; echo =$c; done
Hint: Append | column to columnate list.
This 256-color lookup table can be also found at the Wikipedia page as follow:
The short answer is that you can find on the web tables of colors and match them up to the color number.
The long answer is that the correct mapping depends on the terminal —
The 125 is a parameter to an escape sequence referred to as setaf in the terminal description. tput attaches no particular meaning to the number. That actually depends upon the particular terminal emulator.
A while back, ANSI defined codes for 8 colors, and there were two schemes for numbering those. The two are seen in some terminal descriptions as the pairs setf/setb or setaf/setab. Since the latter has the connotation of "ANSI colors", you will see that used more often. The former (setf/setb) switched the order for red/blue as noted in the ncurses FAQ Why are red/blue interchanged?, but in either case, the scheme was established for just numbering the colors. There is no predefined relationship between those numbers and RGB content.
For specific terminal emulators, there are predefined color palettes which can be enumerated easily enough — and can be programmed using these escape sequences. There are no relevant standards, and you will see differences between terminal emulators, as noted in the xterm FAQ I don't like that shade of blue.
However, convention is often confused with standards. In development of xterm over the past 20 years, it incorporated ANSI (8) colors, adapted the aixterm feature (16) colors, added extensions for 88- and 256-colors. Much of that has been adopted by other developers for different terminal emulators. That is summarized in the xterm FAQ Why not make "xterm" equated to "xterm-256color"?.
The xterm source-code includes scripts for demonstrating the colors, e.g., using the same escape sequences that tput would use.
You may find this question/answer helpful as well: RGB values of the colors in the Ansi extended colors index (17-255)