Wearing pink and green is no problem, as long as it's not too "springy" for the season. (Personally, I would have loved to see girls in DZ colors at my wedding!)
Just don't wear white or red. White is (obviously) for the bride only, and red isn't supposed to be worn because it is traditionally viewed as trying to draw attention away from the bride. Black used to be a no-no also, but it's becoming much more common to wear it now. Hope this helps!