OK, so the term "perfect" really is a bit of a misnomer, as what is perfect for one baby may or may not be perfect for another. Designing the optimal nursery for your new arrival involves a lot of different aspects, from furnishings to lighting, from safety equipment to accessories and fixtures. However, one of the most important aspects to consider is the color scheme you'll be using. The color palette you choose for your nursery affects the baby in a number of different ways, both psychologically and physiologically, so making sure you have the right colors surrounding your new arrival should be one of the earliest tasks on your "being a good parent" checklist. It sounds more complex than it really is though, so relax and enjoy the learning experience.
You'll hear experts tell you that newborn babies have limited color recognition capabilities, and for their first few months, can only recognize monochromatic schemes of black, white and gray. Once the baby's visual acuity starts developing, the color red becomes recognizable, followed by blue, then greens and the rest of the color spectrum. This may lead you to believe that colors for a newborn aren't important, but nothing could be further from the truth. Unless you enjoy painting - a lot, you're actually going to be preparing yo0ur nursery to be optimal for the first 2-3 years of the baby's life, so you may have a newborn now, but you need to plan for the toddler that will be coming soon.
Many parents choose their nursery color scheme based on traditional gender specific roles; blue for little boys and pink for little girls. You should look past the social norms though and choose the colors that you feel will provide the best atmosphere for your baby's first few years. There have been numerous studies involving the psychological and emotional effects that colors have on human beings, from babies to adults, so if you're a hardcore research type of person, you certainly will not lack for study material. A few basic color psychology papers to consider for research purposes are:
Psychology of Color, by David Johnson: http://www.greenwich.k12.ct.us/uploaded/faculty/lisa_dempsey/Psychology_of_Color.doc
Color Research and Application, by Zena O'Connor
In short, certain colors will elicit a specific emotional response. Blues and greens are often used in nurseries because they most often have a calming and soothing effect on young eyes and minds. Red is a more active color, and can help develop certain areas of the baby's brain. Avoid using yellow as a primary nursery color, as yellow has been shown to cause babies to cry more often. The color brown implies security and protection, and can impart a feeling of safety in young minds. Since your baby will likely be using this room well beyond their first few years of life, don't go too terribly overboard on the pastels and baby-specific colors, as they might not hold the same appeal to your child once they get past their baby years.
No matter which colors you choose for your nursery palette, coordinate properly, matching and accenting your wall colors with the fixtures, furnishings and nursery accessories. With a little forethought and planning, you can create the perfect atmosphere to nurture and help develop your baby's eyes and mind to give them an emotional head start as they run with the human race.