How to set the button color of a JButton (not background color)

Question

I have a JButton that I would like to change the background color of to white. When using the Metal Look And Feel, I achieve the desired effect with setB

Answer 1

but I still think that (modified but by Darryl) is correct UIManager.get("Button.gradient"), because would be crossplatform

EDIT: correct answer would be - Nimbus or some Custom L&F, why reinvent the wheel (by Rob)