They're supposed to be a nice bright orange color but apparently the recent ones have been red instead. Actually, I think this makes it easier to see because if you see what looks like a normal PC, you'd be more likely to assume it was a PC whereas this is definetly not a PC so you'd be more careful and look more closely. The red flange is very visible. I stuck this in one of my lights. They're not very noticable in Coopers though because Coopers have that recessed PC socket. I like the late 90s Fisher Pierce open caps best. They're a nice bright fluorescent orange that stands out like no one can imagine.