Here you can find the source of darkerColor(Color c)
public static Color darkerColor(Color c)
//package com.java2s; /*//from ww w . jav a 2s .co m * Copyright 2003-2010 Tufts University Licensed under the * Educational Community License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. You may * obtain a copy of the License at * * http://www.osedu.org/licenses/ECL-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an "AS IS" * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express * or implied. See the License for the specific language governing * permissions and limitations under the License. */ import java.awt.Color; public class Main { static final double sFactor = 0.9; public static Color darkerColor(Color c) { return factorColor(c, sFactor); } public static Color factorColor(Color c, double factor) { return new Color((int) (c.getRed() * factor), (int) (c.getGreen() * factor), (int) (c.getBlue() * factor)); } }