oh-my-zsh/lib/spectrum.zsh

# A script to make using 256 colors in zsh less painful.
# P.C. Shyamshankar <sykora@lucentbeing.com>
# Copied from https://github.com/sykora/etc/blob/master/zsh/functions/spectrum/
 
typeset -AHg FX FG BG
 
FX=(
reset "%{%}"
bold "%{%}" no-bold "%{%}"
dim "%{%}" no-dim "%{%}"
italic "%{%}" no-italic "%{%}"
underline "%{%}" no-underline "%{%}"
blink "%{%}" no-blink "%{%}"
reverse "%{%}" no-reverse "%{%}"
)
 
# Build the tables with array operations instead of a 256-iteration loop
() {
setopt localoptions noksharrays
local -a codes fg bg
codes=({000..255})
fg=( "%{"$'\e'"[38;5;"${^codes}"m%}" )
bg=( "%{"$'\e'"[48;5;"${^codes}"m%}" )
FG=( ${codes:^fg} )
BG=( ${codes:^bg} )
}
 
# Show all 256 colors with color number
function spectrum_ls() {
setopt localoptions nopromptsubst
local ZSH_SPECTRUM_TEXT=${ZSH_SPECTRUM_TEXT:-Arma virumque cano Troiae qui primus ab oris}
for code in {000..255}; do
print -P -- "$code: ${FG[$code]}${ZSH_SPECTRUM_TEXT}%{$reset_color%}"
done
}
 
# Show all 256 colors where the background is set to specific color
function spectrum_bls() {
setopt localoptions nopromptsubst
local ZSH_SPECTRUM_TEXT=${ZSH_SPECTRUM_TEXT:-Arma virumque cano Troiae qui primus ab oris}
for code in {000..255}; do
print -P -- "$code: ${BG[$code]}${ZSH_SPECTRUM_TEXT}%{$reset_color%}"
done
}