Okeydoke, here's how I see it. Ping is simply the overall connection speed twixt you and the server in question. In-game lag, however, can be caused by other things...like the server's actual operating speed, which is (due to the bad memory stick) much slower than it has been.
Dunno how it relates to the yellow and red icons, though...there've been times that I lagged out, and I can't remember my ping EVER going above 200! (I'm in central Texas, btw)
good point...I thought of that too, but, I'm starting to think it's my machine, because it doesn't appear that anyone else is having enough of the same type of issue to post about it.