Of all the things I've shared concerning decorating a child's space, the most important tip to remember is this: "involve your child in the process".
I cannot stress enough how involving your child will make a huge difference from them accepting your color scheme to them keeping their room neat and tidy. When you involve your child in the process, it will instill in them a sense of ownership and a sense of pride.
So, go ahead, don't be shy, ask your child what he or she thinks, you may be pleasantly surprised.
Enjoy your space, Rena