This grey living room with floor to ceiling bookcases uses a very uniform shelf structure but displays the books themselves in a random, jumbled way, creating a unque and interesting feature wall. I like the grey shelves
This is a nice-looking living room with smaller rug. Perhaps the key is to frame the rug with sofas / sofa and armchair combo / sofa and the window. And another trick is to fill up the room so the size doesn't look awkward.