i want its colour be happy and suit.
What colour are the rest of the things in the room? I would say a medium gray will be good....
a nice shade of red. Go to the sherwin williams website and look at their color visualizer online..you can choose from all their paint colors. Just know that it's not the wisest thing to design a room around curtains. It is easier to change your curtains that to change your wall colors, so you may want to think about the wall, and then curtains.