Basic Newbie question

[jasemilly]

I have a real basic question but I can't find an example or tutorial out there. I want to make a half circle, that changes has two colours. One side one colour the other the other side the other, with the dividing line moving through the arc(hope that makes some sort of sense) thanks for any help jasemilly.

 

[hawkeye]

I'm not real certain what you're after, something like this?

 

[jasemilly]

thanks, sort of ish. But the centre would be hollow, I hope to make a logo. This will be the perimeter the red at the bottom will be solid and as it moves to the top, the green will appear and become the main colour at the top of the arc, a bit like a colour wheel.