Don't do it!
Paintball is almost unique (well, in a small minority) of sports where there is no gender segregation. Why? Because there doesn't need to be, men and women can be equally good at it, there's no physical contact, and there's no issue of perceived difference in stamina (like tennis - 3 sets for women, 5 for men?) Introducing discrimination into paintball on any "artificial" grounds would be a backwards step and would just drag us, from the enviable position of a "new sport", back to the state of longer-established sports where many rules are more a result of tradition and Victorian moral values than of actual necessity.
I am proud to be involved in a sport where none of the usual boundaries are relevant, and to impose segregation would be shameful. However, if people
choose to play in teams with particular constraints (as Darkwerks points out), that's their choice, as long as nobody's forcing them into it.
---RANT---
My personal feeling is that any form of artificial discrimination is unjust, including the various guises that positive discrimination has been dressed up as in the name of politically correct bull****. I grit my teeth every time I see a recruitment advert highlighting "special recruiting days for ethnic minorities", with a footnote explaining how the company is an "equal opportunities employer." Well, if equality means giving minorities separate recruiting days, why not give them a separate section of the bus to sit? Or maybe the town planners should cordon off a separate area of a city for them to live, to ensure everyone is treated equally?
Grrrrrrr.
---END RANT---