As a designer I love color but there is something very calming about neutral tones. I like to plan on the tints, tones,and shades of a color and use them to add depth and dimension. One of my favorite things to add to a room, especially a room with a neutral pallet is TEXTURE!!!
The elements of texture are a must for a neutral room thats where you get your interest from.
Another must for a neutral room is contrast. Playing with the light and dark colors for the spectrum create drama and draw the adding adding interest.