Check linux/unix terminal color

Jimmy (xiaoke) Shen
2 min readFeb 29, 2024


awk 'BEGIN{
s="/\\/\\/\\/\\/\\"; s=s s s s s s s s;
for (colnum = 0; colnum<77; colnum++) {
r = 255-(colnum*255/76);
g = (colnum*510/76);
b = (colnum*255/76);
if (g>255) g = 510-g;
printf "\033[48;2;%d;%d;%dm", r,g,b;
printf "\033[38;2;%d;%d;%dm", 255-r,255-g,255-b;
printf "%s\033[0m", substr(s,colnum+1,1);
printf "\n";

If your terminal support true color (24 bits color), you can see this (Mac iTerm)

if it does not work, you may see something like this (mac default terminal):

How to get true color on Mac?

Install iTerm will work.

How to have true color on linux?

In the linux server, the issue have a good change caused by the screen or tmux.

For screen, looks need to use a higher version (have not check this yet).

For Tmux, add the following to the config file:


can solve the problem [2]

set -g default-terminal "xterm-256color"

# make colors inside tmux look the same as outside of tmux
# see
# see
set-option -ga terminal-overrides ",xterm-256color:Tc"