I'd say: VERY BAD IDEA!
If you want a board with a certain color scheme, then buy one that matches that scheme as good as possible. But don't mess with parts that you don't have a clue about.
This is not meant as an offence, please don't misunderstand me. I'm only concerned about operating safety of the board. If you should accidently cover thermally sensitive parts in lacquer, or if you should get some lacquer inside the slot(s) (which most likely will happen with what you are planning to do), it would be highly possible that your motherboard will go up in flames later. Due to thermal overload, or perhaps due to a power contact that has increased resistance because of some of the paint being stuck there, or something like that. You can't foresee things like that. Especially if you don't really know what you are doing.
Just my ,but think about it. Would that mod be worth the risk? Really think about it!