No matter what pigment you add (unless it's black and use also use aluminum powder), epoxy will yellow.

The boat I have now had the beams previously bedded (by POs) with gelcoat. It's holding up just fine and where it oozed out it matches the boat perfectly.

I also just wax the beams with four or five coats of a good carnuba wax. I've never had a problem with them releasing (you have to go to some advanced etching to get epoxy or polyester resins to adhere to aluminum).