Has anyone noticed that when a character is slowed or diseased that their paper doll turns a yellow-green. It freaked me out the first time I saw it.

Really? I did not know that :p I´ll check it out next time something like that happens.
(I guess that if you are a Half-Orc, you would not notice anything, aye? :D )

Yes, their skin turns to grey or green. I got a question about poisoning. The green slime in BG1 was an almost harmless creature excepted that it infected the party members who failed save vs. death with an awful disease. After a while the infected creature exploded and a new green slime was born(yukk). Does this apply in BG2 too?

I haven't seen that happen, well there aren't that many slimes in the game anyway. What we're talking sewers and the stint with the slimes in the Drow City, those come to mind first and that's about it.