I've noticed, that some of the toggle switches (e.g. DC Switch or the four Hydraulic Pumps) have a red Background whereas others (e.g. GEN1 and GEN2) are unpainted. Here you can see what i mean. Is there a special meaning to the red color? First i thought that systems marked with red require a running ENG or APU. But the red on the DOME Light switch obviously does not match.
There isn't actually any particular meaning to those colours. Those switches have a rubber boot at the base to seal out moisture and outside dust, etc, and the rubber happens to be red because that's what the supplier used. Lever Lock switches like the Gen switches don't have a visible boot (the seal is internal) and a couple of the other ones have no boots or boots that are grey rubber because that happens to be what that particular switch came with.