It shouldn't be a problem i don't think. If i was going to do it i would sand them down first, adhesion promoter, then black or whatever color then a couple of coats of clear. Trim paint should work. The handles get used a lot on the underside not so much the top.
EDIT: When my tailgate handle broke off we painted it with rustoleum satin black cause we attempted to fix it. It was only on for a few days but it didnt wash off or anything.