BWalmerGreen = Mods (people who patrol the forums, edit posts, move threads, delete threads).
Red = Admins (people who run the site in various forms, but they're basically the main "employees" of NS)
Purple = Content team members (news writers, photographers, video producers, gear reviewers. These people were selected to help put up content on the site, some do get paid for it).
Orange = Industry folk (athletes, team managers, company accounts, ect)
Pink = Women
*Note, some mods are various other colors as well, for example I'm currently purple, but I'm also a mod, there are some blue,pink and orange mods as well. Admins also have mod powers.
As far as the symbols, those are donators. The symbol has to do with how much you've donated. I believe the green $ is $5, the silver $ is $15, the yellow $ is $25, the yellow $$ is $35, and the gold coin is $50 (I could be wrong on those numbers, I can't remember anymore).
williamelliott1if the pink means women then NS is an absolute sausage fest, its like .7%