Android - How to draw an arc based gradient

Question

I am trying to create an arc (variable number of degrees) that gradually goes from one color to another. From example from blue to red:

Answer 1

To add to Yoav's solution.

On my Galaxy Nexus 4.2 stock Android, the solution given doesn't work.

If the array doesn't contain a 0.0f and 1.0f, it appears to be ignored.

My final solution was:

int[] colors = {Color.RED, Color.BLUE, Color.RED}; 
float[] positions = {0, Xf/360f, 1};