Hi..in reference to MV lamps being green or sometimes even bluish white as some have described...mine isn't any of those colours. It's bright white with a small tinge of green, that's about it so here's the video to show what I mean

http://www.youtube.com/watch?v=bAONaV0huBw

IMJ

Perhaps you overdrove this lamp. In a MH with a slow run-up speed (When several second elapses between the end of the vaporising of the mercury and the start of the halide radiating), these lamp also turns pure white before the halides actually starts to radiate. This is accurs in slow run-up Na-Sc lamps and in rare-earth (Without thallium iodide) daylight lamps that have a 5 min of run up time. This is probably cause because the continuum in their spectra increases slightly above the intensity of the high pressure mercury spectrum. Perhaps the same phenomenon accured also in your lamp. You can check the spectrum of your MV lamp to realise why its produce a bright white color despite it isn't a MH lamp.

My clear lamps themselves also aren't greenish, they are more likely cool white. It's only after you shine the lamp on something (wood and skin produce the most notable effect), it becomes unnatural greenish color, probably because the materials absorb the deep blue and purple lines more than the green and yellow ones.

Digital cameras see the lamps greenish because they see the yellow double-line more greenish than it really is, and probably attenuate the blue and purple lines too much.