Or as I mentioned before, replace the existing bulbs with white LED's and add colored festoon bulbs in separate holders into the fixtures, they are large enough to accommodate. Just run a separate 12V supply to the colored bulbs so you have a choice of brilliant white or color. That way you don't have to replace those nice hardtop fixtures. It works well. Got everything from Super Bright LED. Don't forget, heat is not an issue with LED as it is with halogen.