My Macpro 15 Mid 2012 recently traveled some of Europe via good old DHL. When I got it back most of the displays pure white colour is a pixelated sky blue, though there is a white shadow after some texts and windows (pics attached). Soon as I reopened it at the Mac store the problem had resolved itself, but once again its back a week later. Im guessing its been hit and the gfx card or the like is damaged, the problem is coming and going, strange. Can anyone tell me exactly what the issue is so I can take the next step in getting it sorted. Im traveling and awhile away from a Genius Bar or Service center. Any help would be much loved.