The color wheel can only take a garden so far. When it comes to pairing hues, it is certainly a helpful tool. But too often, using colors, not picking them out, stumps gardeners the most. As a designer, I don’t believe in rules or obsess over color theories. In my experience, almost any color combination can work. I do, however, design within a few basic parameters. These self-imposed restrictions strive for the same goal: to establish a sense of order.