changing the color scheme

Is there any easy way to do this rather than just copying style.css to mystyle.css and trial and error. I want to go from a brownish scheme to a nice neutral gray, gray white, charcoal gray type scheme. Basically various shades of the very top bar and very bottom bar you have by default. Do you have existing alternate color schemes?

I’m trying to do it by just trial and error and replacing all the hex colors with new ones but it’s kind of tedious and difficult and I’m missing some pesky browns that are messing up my scheme that I can’t seem to find.

I’m just thinking there must be an easier way.

Thanks