Light can pass through some materials. An example of a material like this would be glass. It cant go through all materials. When materials let light through, we call that transparency.
they deflect heat
You can buy non see through curtain room dividers and curtain racks at your local Wal Mart. You can also visit their website at www.walmart.com.
Is it good to make YOU stay in a dark room? He's not going to like it any more than you do.
Curtain rods don't have to match the color of the furniture. You can however coordinate the curtain rod to match the room's theme. There is no need to match monochrome or exactly the furniture in the room.
Repainting it would be the most obvious answer, however, it might not be your desire. To make the creme color look whiter place dark objected in the room. Dark brown towels, shower curtain, rugs would be a striking contrast and cause the cream colored walls to be lighter.
make a movie out of it
It probably would make it seem smaller. if darker colors like Brown and dark green do, than really so would dark blue. Any dark color will make a room appear smaller because there is not much reflection of of it. White makes a room appear larger.
because you never draw anything in it XD
curtain
Get under the covers and try not to make any sounds.
I know nothing about a curtain, perhaps you are referring to a movie set, or are you talking about his bedroom window?
Dark colours would make it appear smaller.