No, I’m not talking about that little kerfuffle with Kerr-McGee back in the ’80s.
There’s areason that radioactive waste signs are purple and yellow. Purple and yellow are complementary colors — colors on opposite sides of the color wheel — like red and green or orange and blue.
They compete for the attention of the eye, and so accentuate each other when located close together. On radioactive waste signs, they screem for attention.
If I were a better designer, I’d take advantage of that. But I do notice when it occurs by happenstance.
Euphorbia and allium…
Purple (columbine) and orange (coral bells) have similar effect, though they aren’t exactly opposites on the color wheel.
Tradescantia with its own purple flowers and some columbine nearby …
More purples that I should team up with some yellows. Geranium … [Update: That’s Geranium renardii “Nätnäva”, judging by pix from Ken in Sweden.]
Closer …
Chives and cow parsnip.