Was wondering, if you just spray part of the car eg a black roof or whatever, do you have to declare it as a respray?

I know you have to inform the insurance company and i believe the DVLA of any full respray, just wondered if you have to pay for it at all? Just wondering about cheap, effective mods for a car thats all.

I think it'd be a case of you ring them up and tell them, they say "fine don't worry about it".