Here you can find the source of assertColor(int color)
public static void assertColor(int color)
//package com.java2s; //License from project: Open Source License public class Main { public static void assertColor(int color) { if (color < 0 || color > 255) { throw new IllegalArgumentException("Color outside of range 0 - 255"); }// w w w . j a v a 2 s.com } }