Color for my baby daughter's nursery.....?

My husband and I have decided to paint the sky, clouds, sun on my daughter's ceiling....any suggestions on wall color? I am not sure weather I should go with relaxing colors such as light greens, blues, periwinkle or lilac; or with bold stimulating colors such as yellows, etc. Most of her nursery is clic pooh (different themes of clic pooh, i didn't want everything matching!!)...