Java tutorial
//package com.java2s; import android.graphics.Color; public class Main { /** * Darken a color by the given percentage * @param color the color to darken * @param percent the amount to darken the color by. In range 0-1 * @return the darkened colour */ public static int darken(int color, float percent) { float[] hsv = new float[3]; Color.colorToHSV(color, hsv); hsv[2] *= 1 - percent; return Color.HSVToColor(hsv); } }