I have no qualms admitting that I have strong opinions on color. While I dislike orange, I can still appreciate it when it's used well (just not in my garden). Recently, Frances at Fairegarden, got me thinking about color combinations. It's not so much the hue that is the issue, as it is the intensity and purity of the colors to be combined. I might have a sensitive stomach, but strong yellows with washy, grayed purples or blues, like cool pinks with orange, are a nausea-inducing sight to my eyes. The lighter hue should, in my opinion, be lighter in intensity than the darker hue to which it is paired.
I cut pansy and viola blooms in three different shades of yellow and compared them with the mauve bloom of Clematis 'Betty Corning'. They are arranged from the subtle to the ill-suited.
It's not that the yellow is bad, it's just that it's wrong with that mauve. The yellow is too dark for the light tint of purple.
Now, isn't that better?