What do I need to do if I want to create bouncing balls of different colors?

Color is fixed while creating the renderer.
Code:

styles: {
// set colors for the circle bodies
'circle' : {
strokeStyle: '#ee405c',
lineWidth: 1,
fillStyle: '#ee405c',
angleIndicator: '#ee405c'
}

Is it possible to override this while creating circle bodies?
If yes, how?