Let's all get out our color wheels. What do you see, directly across from red-violet? Yellow-green, of course. Mother Nature doesn't need to consult a color wheel. She knows to choose a lively shade of almost-chartreuse to set off the petals of this particular clematis. Look closely and marvel at how each petal has three distinct members of the purple family, but not the three that most of us would put together for a painting or a quilt. Add the drama of a deeply shaded background and you’ve got yourself a real color story.