We're doing the same thing...not finding out and going very neutral. I would love to show you a picture, but it's not finished! We are going with the Moo Moo Baby bedding set by Lambs & Ivy. It has the cute barn yard theme that I wanted plus muted primary colors (except the red, which is VERY vibrant). We have the border that matches the bedding. I think the plan is to put the border about 4 feet up, and then paint on both sides. The top will be a nice sunny yellow, and the bottom a light, grassy green. We're shopping for nursery furniture on Monday, so I'll know more then!
Good luck, let us know how it's coming!