Red: reds add a sense of warmth to a room but they can also be over stimulating. Try avoiding it all over the room, maybe just add it to one accent wall or use the color red to add some energy in the room by decorating with accent pieces such as, lamps, mirrors, frames, pillows, bedding, etc. Using bright reds help give your room a burst of energy, just be careful how much you red apply to avoid headaches
Orange: Oranges still add warmth to a room. Softer tones create ha cozy feeling. Make sure to use a lot of light in the room to avoid cramping.
Yellow: Yellow evokes feelings of happiness. Softer yellows are more calming and soothing, opposed to brighter yellows that are said to cause your muscle and mind to work more, therefore causing discomfort for babies.
Blue: soft blues are known to be the best color in baby rooms because it provokes the baby to sleep. Its a calming and relaxing color.
Green: Greens promote feelings of well being and peace. Use it with a red or orange to add some energy to the room.
Sources: creative-baby-nursery-rooms.com, ezinearticles.com,