CHE's are a good option for no light, but I've used many black or red incandescent light bulbs & my snakes* enjoy basking under them, no problem I can see?
*various rat snakes & a spotted Aussie python, all of which spend a lot of time on their branches.
Problem with CHE's is that I understand they wear out fast if you dim them, & they all throw out WAY too much heat to use the way I do...I don't want my snakes
to be roasted, plus that wastes energy. ALL my lights are on rheostats (lamp dimmers) & frequently adjusted by me as needed for their comfort. The wattage I'm
using is more like 20 watts, while the CHE's are mostly 50 or 100 watts (or so I've seen?). Something to consider...