Port at least some of Ico's important tweaks from default.css to the other styles.

This ports some more of the changes in the latest default.css to the gui presets. It's admittedly a half-hearted job, done mostly mechanically. Especially the colors in the inverted styles need further tweaking. But this should make most styles look a lot better and more in line with default.css, and in any case it will make Ico's job easier when he's ready to tackle them.