It's well-known that many animals use colour to signal to each other (the classic example being baboons' bottoms), and of course this applies to humans too. We have the additional advantage that we can change our colour scheme without application of any nasty hormones.
I think I've identified one interesting example of this. It's noticeable in (British, financial-sector) offices that the colour pink is rarely worn by guys - unless that guy is a manager.
My best guess is that this originated as a statement of independence - the guy is signalling "I'm so powerful/self-confident that I don't need to obey peer pressure. That's a message that would be expected to propagate within the management community (because they like to think of themselves as standing out from the crowd) but not outside it. It's like deliberately picking the wrong urinal.
If I've noticed this trend, other people probably have too, so I suspect that the fashion is evolving into a way for management-inclined individuals to make their presence known to each other. In a spirit of scientific enquiry, I'm going to wear a pink shirt into work today and see if my new boss (who I've also seen wearing pink) pays any attention.
Watch this space.
Update: Nope, doesn't make any noticeable difference apart from getting me the occasional funny look from co-workers. I still think there's a correspondence here between managers and pink shirts, but clearly it only goes one way.
Update #2: Just received some rather good feedback from the new boss at the client company via my boss from the company that's farming me out. Bear in mind that this has passed through two layers of management, so is probably more motivation than message. However, this is the first time anyone has ever used the word "charismatic" to describe me, so I must be doing something better than I usually do.
This feedback provides slight support for the Pink Principle. It's a rather weak data point, but I've at least reverted from "skeptical" to "undecided" on this question.