I was going to powder coat mine but not sure if I should mask of the ribs or if it's OK to coat the ribs also. Just not sure if I coat them if it will cause any belt issues

mask the ribs....

Polishing reflects any color you want . Good question though .

I can't imagine Any powdercoat holding up on the ribs. Mask it it off or anodize the the whole pulley.

anodize would be the way to go

I thought about it buti can do the powder coating for free lol

I agree, mask the ribs or have it anodized.