Java tutorial
//package com.java2s; import android.graphics.Color; public class Main { public static int getDarkerColor(int color) { int alpha = Color.alpha(color); int red = Color.red(color); int green = Color.green(color); int blue = Color.blue(color); return Color.argb(alpha, (int) (red * 0.9), (int) (green * 0.9), (int) (blue * 0.9)); } }