truecolor-test

#!/bin/bash
# Based on: https://gist.github.com/XVilka/8346728

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";
}'