[JesseK]

Camouflaged Jaguars would be uber cool... they're already that terribly-colored brown. That's why we're putting them upside down underneath our electronics board :x You hear this Luminary Micro??? We want black Jaguars!

On a more serious note though, labeling doesn't modify the component itself -- it simply attaches something to it. I would presume that if anyone was so inclined to try to make some proclamation against labeling with this reasoning that they would be forgetting that such a clause would prevent the use of screws to attach any electronics since screwing them in makes some sort of scratch on the electronics which is just about the same thing. I think that's why the word 'reasonable' has to be implied, and the inspectors won't have an issue with labeling so long as you use good practices with it (e.g. don't use the label to go across pins, don't put the label over the fan vent, etc).

If I put myself in the GDC's shoes, I think the rule itself is meant to prevent a team from blaming the FMS for non-responsive control components that have been damaged during modification. Since the only proper way to paint the plastic is to take the Jaguar apart, I can see where that ruling is coming from.