#!/usr/bin/env bash awk -v term_cols="${width:-$(tput cols || echo 80)}" 'BEGIN{ s=" "; for (colnum = 0; colnum<term_cols; colnum++) { r = 255-(colnum*255/term_cols); g = (colnum*510/term_cols); b = (colnum*255/term_cols); 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%2+1,1); } printf "\n"; }'