Like I said, go pick up a few color charts from several different dealers. These charts will have a house painted in the colors shown to give you an idea of how to use the colors together properly.

The trim color is usually lighter or darker than the body, the "pop" color is usually darker than the body. I know this isn't much help, but it's very hard to describe colors and how they play together.

This was from a random Google Images search for "house colors". Look at the 4th house down on the page for an idea of how the colors play together. The trim is lighter than the body, the pop is darker.
www DOT zimbio DOT com/Exterior+House+Colors