bash.256colors.bashrc

function colordemo() {
    # from http://misc.flogisoft.com/bash/tip_colors_and_formatting , slightly modified
    # see also https://en.wikipedia.org/wiki/ANSI_escape_code

    for fgbg in 48 38 ; do #Background/Foreground
        for color in {0..256} ; do #Colors
            #Display the color
            echo -en "\033[${fgbg};5;${color}m ${color}\t\033[0m"

            #Display 10 colors per lines
            if [ $((($color - 15) % 6)) == 0 ] ; then
                echo #New line
            fi
        done
        echo #New line
    done
}