I was recently attempting to do some ORM modelling out of doors, and found I needed to use the "High Contrast White" windows appearance in order to see anything at all. It worked surprisingly well, except that the subtle pink color used to indicate an error with a diagram element was completely invisible. I had to wait until I was back in the office to see that I had introduced several errors into my model.
Naturally, it was only then that I learned to use the Error List window to see the errors, but I thought I'd mention the display problem.