@donkor: I've noticed that too, with one of my DQs. The colours were perfectly fitting without shaders but after selling it to someone with shaders, it was way too dark for him. It helped alot to re-adjust brightness & contrast. Did you try a real semi-transparency of 50% then? Possibly works, too. I haven't found a good thumb rule to apply but maybe us texturers will find one together.
And sorry for being offtopic.