This is halfway between a bug and a "come on, how could the developers EVER have thought of that?" Not sure there's a way to fix it so it never happens, but perhaps someone is feeling like they'd like a challenge.
If you set your primary colour to #ffffff (white) and hit save, the result is that many things are hidden, including the save button. As a result, when you realise your mistake and try to change it back, you can't find the save button.
I know, I know, you have to be a newb to not know where the button is, but in these days of autosave, it could be easily assumed that no save button is necessary and instead the whole system has failed in some weird way.
I fixed it by looking at pictures of how the Admin Appearance page is supposed to look, and realising what I was missing, but I suggest a sanity check could be put in that prevents that happening.
Feel free to ignore this. It was a pretty stupid problem, and easily fixed once I got past worrying that my database had turned read-only. But as I say: maybe someone wants a challenge.
