Why this works?
They tied it all together with a tight color palette. Notice the art, frames and wall all share the same blue, green, orange, brown and yellow. BTW, this process can work anywhere to unify. If you are putting together a room that's looking like a mixed bag, take it back to a few colors. You will be surprised that no matter the style, everything will "work."
(image from Real Simple October 2008)











