Here you can find the source of mixColorWithAlpha(Color base, Color mix)
public static Color mixColorWithAlpha(Color base, Color mix)
//package com.java2s; /*/*from ww w. j a v a2s. com*/ * NimbusHelper.java * (SwingOSC) * * Copyright (c) 2005-2012 Hanns Holger Rutz. All rights reserved. * * This software is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either * version 2, june 1991 of the License, or (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License (gpl.txt) along with this software; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * * For further information, please contact Hanns Holger Rutz at * contact@sciss.de */ import java.awt.Color; public class Main { public static Color mixColorWithAlpha(Color base, Color mix) { if (mix == null) return base; final int a0 = mix.getAlpha(); if (a0 == 0) { return base; } else if (a0 == 0xFF) return mix; final float wm = (float) a0 / 0xFF; final float wb = 1f - wm; final int r = (int) (base.getRed() * wb + mix.getRed() * wm + 0.5f); final int g = (int) (base.getGreen() * wb + mix.getGreen() * wm + 0.5f); final int b = (int) (base.getBlue() * wb + mix.getBlue() * wm + 0.5f); return new Color(r, g, b); } }