Change default theme appearance

I have been able to change some of the colors and text in the default theme so that all of my tables on my web will look the same. It would be really nice if there was an editor so that those changes could be made without having to work in the code for the style sheet and the language file.
I want to reposition some of the elements in the default theme as well. Is there a way to do that without having to manipulate the code?
Thanks.