android: Animate color change from color to color

Combining @zed’s and @Phil’s answer gives a nice smooth transition using the ValueAnimator.

final float[] from = new float[3],
              to =   new float[3];

Color.colorToHSV(Color.parseColor("#FFFFFFFF"), from);   // from white
Color.colorToHSV(Color.parseColor("#FFFF0000"), to);     // to red

ValueAnimator anim = ValueAnimator.ofFloat(0, 1);   // animate from 0 to 1
anim.setDuration(300);                              // for 300 ms

final float[] hsv  = new float[3];                  // transition color
anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener(){
    @Override public void onAnimationUpdate(ValueAnimator animation) {
        // Transition along each axis of HSV (hue, saturation, value)
        hsv[0] = from[0] + (to[0] - from[0])*animation.getAnimatedFraction();
        hsv[1] = from[1] + (to[1] - from[1])*animation.getAnimatedFraction();
        hsv[2] = from[2] + (to[2] - from[2])*animation.getAnimatedFraction();

        view.setBackgroundColor(Color.HSVToColor(hsv));
    }
});

anim.start();                                        

The HSV will give a nicer transition than Androids default color space because HSV describes colors in cylindrical coordinates that nicely separate the color’s properties and allow a smooth transition across a single axis. You can see from the image below that traveling along the H, S, or V directions gives a nice continuous transition between colors.