Java tutorial
//package com.java2s; import android.graphics.Color; public class Main { /** * Get a darker version of a color * @param color the color to be darkened * @param factor the factor by which to darken the color * @return an integer representation of the darkened color */ private static int darker(int color, double factor) { int a = Color.alpha(color); int r = Color.red(color); int g = Color.green(color); int b = Color.blue(color); return Color.argb(a, Math.max((int) (r * factor), 0), Math.max((int) (g * factor), 0), Math.max((int) (b * factor), 0)); } }