"On my laptop which has inferior graphics capabilities, textures often appear white when blended even though they show OK on my desktop PC."
You may need to correct gamma. I used to have a similar problem on my PC with its older hardware (ie. ATI Rage Fury Pro.) It wasn't just blending either; in general brighter parts of the scene were blown out, as though everything above a certain brightness was just clamped to white. I fixed the problem with the following code right after the call to Graphics3D:
SetGamma 255,255,255,255,255,255
UpdateGamma
You may need to correct gamma. I used to have a similar problem on my PC with its older hardware (ie. ATI Rage Fury Pro.) It wasn't just blending either; in general brighter parts of the scene were blown out, as though everything above a certain brightness was just clamped to white. I fixed the problem with the following code right after the call to Graphics3D:
SetGamma 255,255,255,255,255,255
UpdateGamma