mjhjmtu

How can I display colors in terminal to handle hexadecimal color values ?
It can be useful for theming, XResources etc.
For example :

$ command '#FF0000'
// display a red square

I use urxvt, i3wm in manjaro.

You could change the background colour of the terminal with:

printf 'e]11;%sa' '#ff0000'

Which seems to work with xterm, VTE-based terminals (like gnome-terminal), konsole and rxvt at least.

You can also change other colours than the background's if you prefer. Like change the colour 1 and display a rectangle in that colour with:

printf 'e]4;1;%sae[0;41m n ne[m' '#ff0000'

To display more than one colour:

show_colour() 
 for i do
 printf 'e]4;%d;%sae[0;48;5;%dm%se[mn' "$#" "$i" "$#" "$i"
 shift
 done


show_colour black purple green '#ff0000'

That does permanently change the palette for that emulator window though. Use tput oc to restore the default colours.

Other option could be to run:

xlogo -bg '#ff0000'

Or

rxvt -bg '#ff0000'

An alternative:

show_colour() 
 perl -e 'foreach $a(@ARGV)print "e[48;2;".join(";",unpack("C*",pack("H*",$a)))."m e[49m ";print "n"' "$@"

Example usage:

$ show_colour "FF0088" "61E931" "1256E2"

This prints spaces with the given RGB background colours. Note that you must not use # in the RGB code. I leave stripping that if present as an exercise for the reader. ☺

This does not alter the terminal emulator's palette.

Caveat: Your terminal emulator must understand direct colour SGR control sequences. Many do, but you'll find that rxvt-unicode does not.