You can set what messages show there, to some degree anyway. Right clicking the tab should bring up options for it. The +1 skill points one, for example, should be part of Rewards. Turn that off for the main chat thing and that bit of spam should no longer bother you.
No idea how I did that, but I disabled the pink text popups.
The color is always yellow and repeats the messages I cited above.
Now that I really examine it, it does give loot messages too.
You have recieved item XZY (usually anomalies, results of need or greed, loot i get from defeated enemies)
It even does the "non visible" ones over the top of the loading screen and everytime I change maps.
I'm really starting to loathe that bar now.
Ironic that you can "hide" your Rank/XP bar, but the most annoying one of all you can't hide at all!