CSS for painting

I've got a great new idea for an invention, that I just thought of whilst painting the walls of my daughter's bedroom, which is going to take 3 coats, and I'm not totally sure that the colour is exactly what I want, and I can't tweak it a little once I've finished.

A CSS file makes it really easy to change the colours of an entire website all in one go, and saves loads of time. My idea is to have a CSS file for a house. In that way I can try out a colour, and change it if I don't like it. e.g. I can start with this:


.house .bedroom .emma
{
   background-color: FloralWhite;
}


and if I don't like it, I can change it to


.house .bedroom .emma
{
   background-color: PapayaWhip;
}


Haven't quite figured out how to code it up yet though...