Go lang and ANSI 256 colors

color.go

package main

import (
	"fmt"
)

const Color = "\033[38;5;%dm%-4d\033[39;49m"

func main() {
	for row := 0; row < 16; row++ {
		for col := 0; col < 16; col++ {
			code := row*16 + col
			fmt.Printf(Color, code, code)
		}
		fmt.Println()
	}
}