Well, after my shower this morning I went up and took another look, and the flame is much different now. It’s pretty much all blue. I guess it was just looking a little off at cold start.
There is plenty of air for combustion. It’s in the attic with plenty of space around it. The attic is vented at the soffits and ridge.
Thanks for the LED answer. I knew, of course, that the electricity was coming from the heat somehow, but I didn’t know the word “thermopile”. Now I do. 🙂