praxis: dooes it use blue on the BUM files, though? This doens't have to be for Tron, it will work for anything you want to reflect light in a particularly unnatural way. I'm going to experiment with using it on a transparent object to see if I can't get diamondlike specular (the real term specular, not the 3D jargon specular) effects. I may also play around with the possibility of getting somethig that looks like real snakeskin opalescence if I can ever get my photographer to take pictures of the snakes for the Python textures I have projected. (*sigh, I started that a month ago and haven't gotten any time from him -- noggin even gave me a snake so I could do it*) This would also work really well for the lettering on the One Ring, or any runes inscribed on a magic item of any sort. The idea is that by using a colour outside of the gamut that a BUM expects, it forces P4 to render it reflecting light at an impossible angle, i.e. light at >90 degrees to the camera is reflected *around* the surface and back at the camera, not not like it's transparent -- not through, but around. Almost like refraction, but not quite.