It should go away after a few changes, or at least after you move a little bit. Maybe it's a small glitch... in which case it hopefully goes away once you progress a bit and get another icon. So just try proceeding and let's hope it solves itself.
- Joel, Frozenbyte team, developers of Trine 2: Director's Cut
Its probably an update to fix the gamma level issues of the wii u version.
Yes, that's pretty much what we mean by the improvement. It will have better colors after the update (and not just colors, it affects quite a few things, it's a rather big difference actually).
Anyhow the update has been done so now we're hoping it doesn't have any technical issues, and can then be released next week. Fingers crossed.
- Joel, Frozenbyte team, developers of Trine 2: Director's Cut