depending on how long it was off it could take several minutes for the backlight to fully warm up.
I think there's a definite tint to all macbooks. I use the regular LCD profile it came with. If you try any of the RGB profiles, you'll notice a blue/purple tint to everything. I think the default apple profile tends to be a tad warm. that's all.
Are there any thrid party profiles available for further tweaking on a mac? Or can you tweak the standard ones yourself?