especially with something which provides a slight tint/hint of warmth - lampshade, or gel, or whatever.

Yeah, but the problem here is that we're talking about pure glass covering, or none at all. We've already switched some of the lamps with shades over to CFLs, and those generally work fine, but the ceiling lamps under glass don't look right, and those are the majority of the house. So the actual bulb color is crucial in most of these cases...