#fff is pretty generic. :-P Kidding aside, for what it's worth, the .thank-you colors are the same or similar to ones used elsewhere in this same stylesheet and in other CSS (e.g. the semantic droppable spaces), and come from mock-ups that precede the OERPUB logo. I'm not sure if by generic you mean a) will go with most things, b) have a browser-supported name (e.g. lightgreen), or c) something else.