Hi Greg,
Personally, I don't think you can beat the classic black and silver look. Either that or black and bare alloy, but not polished, I think an alloy tank once it's been allowed to dull down a little looks great.
I believe that the paint and color scheme should reflect the bike, in your case it's a cafe racer so the paint scheme should be stripped to the minimum just like the look of the bike.
All the best
Webby