I know this like a one in a thousand type thing, but the other day I ran simulation and everything looked great. Then I ran the part and gouged it. This was because the customers model that I had imported had a very similar color / appearance to the color applied to that operation during simulation, so it was almost impossible to notice that the model was showing through.
My idea is simply to strip the model of any appearance during simulation so that this does not happen. Perhaps this "stripped down" appearance during simulation can also be set to a defined default in preferences.