k2design's Profile

Based on the colors you like do to pictures of the place, and you inclination towards a colorful friendly space this is what I would do:

1. Paint the center wall either a bright blue same as one on the cushion and boxes under the desk to create contrast with the natural colors in the area or a bright orange taken from the same places as the blue one but incorporating this spring-like feel.
2. The walls on the sides(the ones with the shelves) I would actually keep the shelves and go with the colorfuol here. Painting each one pink, blue, orange, green and white/beige creating a colorful scene and accentuating the wall creating a perfectly modern and upbeat contrast against the brick wall in the othe end.
3. Above the fireplace, is your choice to either keep the triangle or lose it to implement it in some other place through the apartment. If you decide to remove it I would put a round mirror with a mirror-pieces frame to again contrast with the rectangular shelves on the side.
4. Enjoy!

PS. I made a picture on how it would look! :)