The most eye-catching part of a garden plant is its flower, and the most captivating element of a bloom is its color. You might think then that designing a garden should be an exercise in painting with flowers. This idea once held a lot of sway, but color-driven garden design is, by and large, a dead duck.
Gardeners today are more relaxed about their plantings and are driven less by color schemes than the desire for naturalistic effects. We are still drawn to flowers and have our own color preferences, but the need for elaborate, color-coded borders has generally vanished.
There are ways to pinpoint plant color — the most famous is the Royal Horticultural Society Color Chart, essentially paint charts with holes in them for matching chips directly with a flower — but I have never seen a gardener in the United States use one.
This retreat from overt color design doesn’t mean that we should abandon our interest in color theory. Every gardener needs to know how color works.