I dont have a very big room, and one wall is mirrored wardrobes, but the colour scheme has to go with my bed, which has a high, padded headboard and frame in chocolate brown leather and is the main focal point of the room.
I've always favoured a peaceful sky blue for a bedroom, but I'm unsure that goes with chocolate too well. You may want to consider a sunny lifting yellow shade instead ?
Id say duck egg blue is nice with brown as is light pink or a lime green! As does red actually! How about neutral walls? White/cream/ mocha and then accesorize with a colour of your choice- curtains, cushions bedding vase etc xxxx
I dont think yellow and brown go well, it reminds me of a rather runny bottom condition. Duck egg is perfect. The wall behind the bed could be wallpapered in a duck egg and dark brown print, not too large a print if the room is small, and the other walls a soft duck egg. Lovely ! Have a look in B&Q at wallpapers and get some samples to try at home. Curtains or blinds could be cream or white.