You're wrong. You're not a n00b, you're a newb (apparently there's a difference, although I've never cared much about it).
devious is quite right, yellow damage is that of which you get from using abilities. White hits, in your case (although not in any other case than warrior and bear-druid) generate rage. So, getting a white hit, and then using Slam is a good thing! A really good thing.
Anyway, when ever you see a white hit hovering just above you character, you'll know it's a "white hit". Same goes for yellow; when you get a yellow hit hovering above your char, you have a "yellow hit".
Excuse any miss-spellings, I'm drunk out of my mind.