#!/bin/bash

if [[ ${#@} == 1 ]]; then
    red=$1
    blue=$1
    green=$1
else
    red=$1
    blue=$2
    green=$3
fi

declare -a outputs=( $(xrandr --query --current | perl -nle 'm{^(\S+) connected} and print $1' ) )
for o in "${outputs[@]}"; do
    xrandr --output "$o" --gamma "${red}:${green}:${blue}"
done