Android :: How To Write Centered Multi Colored Text To Canvas

I am writing to a canvas from a thread.

public void draw(Canvas canvas) {
Paint p = new Paint();
p.setAntiAlias(true);
p.setTextSize(30);
p.setColor(Color.WHITE);
p.setTextAlign(Paint.Align.CENTER);
canvas.drawText("Centered", xCentre, yCentre, p);
}

My problem start when I have a multi colored SpannableStringBuilder which I want to write to the canvas, and I have no idea how to do this. SpannableStringBuilder has a drawText() method which I have been unable to use. Or is there some other method to write a string to a canvas where some of the letters have a different color?