Question: Is there any kind of rating of temperature on bulbs when you buy them? Or any significant difference from one halogen to another in terms of actual ambient temperature?

Reason: I put Luminics Hyper Yellow bulbs in my fogs and the reflectors got cloudy and the diffusers fell off. I've seen threads where this happened anyway to other folks. So I'm wondering, will this happen again if I try for yellow bulbs in my fogs. Or did I just have a bad pair of fogs and no big deal.

Is there any way to tell if other bulbs are significantly hotter than the OEM ford supplied bulbs in the fogs when you get them?