Don’t you agree that there was far too much color in the previous version, with its big pink header? Well, even if you don’t, it’s too late. It’s much better this way, there’s more gray, it fits me better, and I think it’s lighter this way (I’m obviously not talking about download times, as there are more and more images and nested tables, but it looks lighter to the eye).

It wouldn’t look so broken while it loads if Mozilla didn’t wait for the last second to download table backgrounds, obviously. But I don’t think anyone in the development team would care about that, considering tables have bad press these days.