Yep. There have been reports of display anomalies involving color changes like this already. Steve knows about it. They have been doing a major revamp of the display code and haven’t ironed all the bugs out yet. --Mitch
http://discourse.mcneel.com/t/viewport-changes-color-when-extruding/25728
http://discourse.mcneel.com/t/another-display-bug/25878/7