White would be the conventional route.

white or the ceiling color you use will be best as you change wall colors over the years you wont need to paint the closets

I also painted all interior closets white. Reflects the lite and doesn't have to be painted when room is repainted.

I do same as Angel. I paint often and painting closets is such a pain -'takes almost as long as the all the other walls out together. Definitely go white and leave future options open.

This is a tough one. White is the safe choice. The logic is that you can always have some colour in the bedroom if you want. Painting around a closet can be tough and a pain in the ass.

That being said here are three pictures showing different options.

I'm a fan of the wallpaper. Once your clothes are in most of it is covered up so it's not as flashy as it looks when it's empty.

Adding some colour isn't bad too. It just depends on if you are going to stay in your house for ever. Or are you renovating for resale. A boy might not like a pink closet.

Have some fun.

Shaun.

Unless you are painting a walk in closet they typically go white. I have had a couple of clients over the years paint them the same color as the room. if you change the room color you don't want to have to empty the closets.

I'm in my forever home, so I decorate mine -- my closets are a bit of whimsy. But if you're planning for resale, or you just like a clean, crisp feel, you can't go wrong with white!

I'd paint them white but if you want to have some fun, you can pick one closet like the coat closet and paint that a fun "pop" color that still goes with the rest of the colors in the room.