Changing the color of a ShapeDrawable ImageView in a GridLayout

Question

I have a GridLayout with 16 dots, which are ImageViews created from ShapeDrawables. How can I set the color of these without creating a new ShapeDrawable?

Here's most of my code:

for (int i = 0; i < dotNumWidth * dotNumWidth; i++) {
        ShapeDrawable redShape = new ShapeDrawable(new OvalShape());
        redShape.getPaint().setColor(Color.RED);
        redShape.setIntrinsicHeight(width / dotNumWidth - dotNumWidth * padding);
        redShape.setIntrinsicWidth(width / dotNumWidth - dotNumWidth * padding);

        // Put Cyan Shape into an ImageView
        ImageView redView = new ImageView(getApplicationContext());
        redView.setImageDrawable(redShape);
        redView.setPadding(padding, padding, padding, padding);

        grid.addView(redView);
    }

    final Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            grid.getChildAt(child).setAlpha(100); // I want to change this line

            child = (new Random()).nextInt(dotNumWidth * dotNumWidth);

            grid.getChildAt(child).setAlpha(0); // and this one

            handler.postDelayed(this, 1000);
        }
    }, 1000);

This is run in the onCreate(), and I wish to change the lines marked above to change the color of the views instead of the alpha. I know this is possible if I replace the view with a new view, but is there a better way to do this?

This is a picture of the dot grid: