The File Browser that is used to insert media and links into the editors doesn't allow for easy skinning. The body inherits from the style.css file and because of this, the file browser is hard to read. In some skins, I have set the body to use the same background and text colors as the pagebody so the editors will display text the same way it will be displayed on the actual pages.
I did see that the form on the File Browser page has a static id of "form1" so I used form#form1 to specify different background and text colors. While this works, it relies on that form ID never changing.
Would it be possible to add classes or IDs to the elements on the File Browser page?