The Ikea Jansjo lamp's neck is so flexible Bill I was able to put the head almost touching the rear element of my FD 35mm f2 lens that I placed on a small mirror to maximize the effect, and it worked like a charm, in fact every time I look at the lens now I can't believe it, I shot some Fuji Provia with it to test it and I projected it and can see no colour caste at all.
Interestingly my eldest son who's a nuclear physicist told me that the yellow caste will eventually come back, but not in my lifetime