You want a good contrast between the background fabric and all the other fabrics (color #1, color #2 and color #3). For the other fabrics (color #1, color #2 and color #3), you can use any 3 colors that you love to work with. You want the fabric for the color #'s to be totally different from each other. It is also good to use a different family for each color #. This mean, for example, you would not what to use two blues, unless there is a strong contrast between the two blues. It is best *NOT* to use directional fabrics like stripes.