If you plan on keeping the car forever, then it doesn't really matter.
If you plan to sell it though, would largely depend upon the buyer, and whether they are appreciate a 70's colour, or if they would prefer something more modern. Browns of any variation are very 70's, so to a young person now who might be interested in buying, probably much more of a negative, kind of like a brown suit.
Bright colours such as shades of orange, yellow, red, green, much more appealing I would think to the majority of likely buyers. White never really goes out of fashion, so that would have wide appeal I imagine.
I have never seen a bright pink P6, which I dare say would look pretty good, and likely appeal to lots of women.
Ron.