Darken Android color.

gistfile1.txt

   public static int darken(int color, double fraction) {

        int red = (int) Math.round(Math.max(Color.red(color) + 255 * fraction,255));
        int green = (int) Math.round(Math.max( Color.green(color) + 255 * fraction,255));
        int blue = (int) Math.round(Math.max( Color.blue(color) + 255 * fraction,255));

        int alpha = Color.alpha(color);

        return Color.argb(alpha, red, green, blue);

    }

This doesn't work, here is a link to a working lighten and darken piece of code https://gist.github.com/martintreurnicht/f6bbb20a43211bc2060e