Random rnd = new Random();
paint.setARGB(255, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256));
<?xml version="1.0" encoding="utf-8"?>
<resources>
<item name="blue" type="color">#FF33B5E5</item>
<item name="purple" type="color">#FFAA66CC</item>
<item name="green" type="color">#FF99CC00</item>
<item name="orange" type="color">#FFFFBB33</item>
<item name="red" type="color">#FFFF4444</item>
<item name="darkblue" type="color">#FF0099CC</item>
<item name="darkpurple" type="color">#FF9933CC</item>
<item name="darkgreen" type="color">#FF669900</item>
<item name="darkorange" type="color">#FFFF8800</item>
<item name="darkred" type="color">#FFCC0000</item>
<integer-array name="androidcolors">
<item>@color/blue</item>
<item>@color/purple</item>
<item>@color/green</item>
<item>@color/orange</item>
<item>@color/red</item>
<item>@color/darkblue</item>
<item>@color/darkpurple</item>
<item>@color/darkgreen</item>
<item>@color/darkorange</item>
<item>@color/darkred</item>
</integer-array>
</resources>