That should have effect on the the material slots in the material editor. Is it the same after you restart max? Try and uncheck Affect Material Editor in the Gamma and LUT and see if that helps.
could it be some bug? For some weird reason, we used to get overly bright material editor spheres from our Chinese studio with all kinds of 3ds Max versions (9.0 - 2009). They would just be bright by default, but other than that everything was normal. I never figured this behavior out though. In my own 2013 install they've…