Phil, those screen shots are awesome! Hell... even the ones with the bad purity look sharp!
You certainly don't have to move a set far to get it out of whack. Here on the ship (back at work again since yesterday), TV's, computer monitors, radar screens... they all get out of whack while changing course. When we go thru the Mississippi River (lots of winding turns), you can actually watch the colors come and go as we turn back and forth. The computer CRT monitors (just two left that haven't been replaced) and the radars see a lot of use with the degauss buttons. The TV's are turned off an on enough to keep them clean.
Not long ago, the 3rd mate told me his TV was really out of whack and turning it off and on wouldn't fix it. I got the chief's soldering gun, waved it in front of the mates screen, and presto! Color fixed again! They "think" I'm some kind of miracle worker.