There are choicees for full sun to complete shade. Be carful to choose perennials that are in scale with your area. Look for contrasting shapes to put near one another.
Flower color is only one of the elements to consider.
Decide if you want a monochromatic garden with shades of the same color, a color coordinated garden, or a wild mixed garden. Look to place pleasing and contrasting foliage colors agaist one another. Texture is another important element in a pleasing arrangement. Look for at least a few plants with strongly contrasting texture. Put them together here at the nursery and if you like them, try them.