As a result of the latest update (3.5.2) I am now seeing the Visual Editor window with a style closer to the theme style as set out in the site's css file. At least now the background is the same color as the theme and the body text is the correct color but the heading tags (h1-h6) are still incorrect.
Personally I think this is progress but I have one client that prefers it the old way - e.g. black Times Roman text on a white background. (Their site has a dark background with white body text).
So I need a way to override the theme's CSS and set the background back to white and the body text to at least black (fonts are not an issue).
Ideally I'd prefer a solution that enables this to be done in a way that future updates to the core wont wipe out the changes.