Slight update: I left it about 24" under a couple of 10W compact fluorescent bulbs while going out to dinner tonight, and when I came back I had gotten a slight coloration (I bought the blue Inkodye). I looked just now and it's a little better, definitely blue. It's working, then, but slowly. Those bulbs are always on, so I'll just let it continue overnight and see how it looks in the morning.

P.E., I think you're right. No documentation anywhere says anything about using light other than sunlight, so it may indeed be UV-sensitive. If someone wants to pay for a suntanning session, I'd be glad to do a more scientific test of UV light vs. non-UV light.

I'll indeed post my results. I had made a gobo a while back from a sheet of overhead transparency film that I'd laser-printed with a nice pattern. I paintbrushed Inkodye onto some 65# card stock (unexposed, it is a translucent white liquid), and sandwiched it with the gobo sheet into a contact printing frame.