One time Routers came in Blue, then Silver, then White/Grey,, then black, then glossy black. There were some red ones also. Slate on the more expensive ones from Cisco. Dust build up form static electric near it.
Should be no problem. Make sure to sand off the old paint before applying the new paint. Then apply a thin coat of carnauba wax followed by a good buff job.
Was serious myself though. Could have sought for a EnGenius if not for its so-so performance, and perhaps Apple's if not for its high price and mechanical fan.