Brewmaster Damage

Whenever im in brewmaster stance my damage on my character pane appears in red. This continues when i switch to tiger stance.
http://i.imgur.com/vDpUTiM.jpg
http://i.imgur.com/Rhyy8at.jpg

However when i switch to my other spec spec (mist) it vanishes
http://i.imgur.com/TPSot2x.jpg

Does anyone know what this is or how to fix it?
thanks!

There is nothing to fix.

what is it though? :/

Brewmaster receives a damage penalty as a trade-off for being tanky and generating threat. Just like any other tank.

ok didnt know that xP thanks!