Nursery advice

I have almost 4 year daughter and 25 weeks pregnant with a baby boy Well my daughters crib is still in our room. We will move both of them once the baby born. Now her room is minnie mouse but i wanna decorate it for both of them. My daughter in love with blue colour. So thinking to decorate thier room with blue and white colours. U dont think that room will be more for boy if i decorate in blue? Any advice? Or what colour u think will be good for them?