Saying "quick & dirty", while intriguing, doesn't explain why?
I replied to this earlier, but the reply seems to have vanished with the latest forum problem. So, I hope you haven't already seen this...
When you create a use account under Vector, data from /etc/skel is copied to the new user's home directory. In Vector's case, this includes a .mc directory which establishes some defaults (including colour settings) for MC. By deleting that directory, you force MC to create a new set of defaults, which will not include any colour settings, so the original defaults will be used.
I didn't suggest that option in the first place because I use MC a lot, and set things up to suit my use pattern. So I would be very unhappy to lose the contents of ~/.mc