Here's my shader in case you wanted to see it. The rgbgen const that I have commented out is what I was messing around with to see if that had an effect, but it seems to only affect the lightness/darkness and not the hue.
textures/000-blake/b_glass
{
qer_editorimage textures/000-blake/b_glass.tga
qer_trans 0.5
surfaceparm trans
cull none
{
map textures/000-blake/b_glass.tga
blendfunc add
tcgen environment
//rgbgen const ( 0.2 0.2 0.2 )
}
}