I've not changed the colours, apart from making the yellowish highlight bar in forum and post lists a bit softer.
I've done a number of small changes which just neaten things up a little - changing spacing between elements and the like. Visually the biggest change has been changing the forum and post icons from square to round.
There are still a number of things undone but which I haven't forgotten about - like breadcrumbs at the bottom of the screen, mark all read on the unread topics list, a theme with inverted colours. I hope they will come in a reasonable time, but in the past couple of weeks I've had serious personal distractions which have taken my mind off them, and which will delay the bigger jobs like new colours at least until January.