The color scheme in this living room seems to have originated with the fabric used on the ottoman as inspiration. The disparate shades of blue & green work well together & give a fresh and informal look to the space. I also love the window & the pediment built on top...V
Color schemes are another big thing in I.D. Too many colors makes the room look, to be frank, ugly. It has no pattern or flow. Shapes can also be a big factor as well. You can choose a "shape scheme", which means choosing similar looking shapes(ex: Triangles and squares; Circles, ovals, and curves). This picture illustrates the importance of color and unity.