Blue: My Favorite Color

Blue has always been my favorite color, and it’s one with a fascinating story. Here are some of my favorite facts about blue:

• Blue light is special. Its wavelength falls between roughly 450–495 nanometers, making it one of the shortest wavelengths of visible light. This is why the sky appears blue — shorter wavelengths scatter more efficiently in the atmosphere.

• Blue pigments are rare in nature. Historically, ultramarine made from lapis lazuli was so valuable it was reserved for important artworks, especially religious paintings.

• Blue protects. In many cultures, blue is the color of evil eye amulets, symbolizing protection, peace, and divine power. Its connection to the sky and water reinforces its role as a powerful shield against envy and harm.

• Blue feels calm (and sometimes sad). Psychologically, it’s associated with serenity, trust, and stability — but it’s also the color of “feeling blue.”

Blue Plants

Blue plants are rare and captivating. Hydrangeas, and my personal favorite, the orchid Cleisocentron gokusingii, show off their blue thanks to anthocyanin pigments. These pigments are usually red but shift toward blue when the plant’s cell sap is more alkaline. Flowers can fine-tune their cell chemistry and vacuole pH to create striking blues, but leaves generally have a slightly acidic pH, which keeps anthocyanins looking red or purple — one reason true blue foliage is so uncommon.

Iridescence: When Blue Isn’t About Pigment

Not all blue comes from pigments. Iridescence is a phenomenon where microscopic structures on a surface reflect light in ways that produce vivid, shifting colors.

We see this in animals, for example, the iridescent pink throats of hummingbirds here in California, and in a handful of plants. Some rare species, like the spectacular “Peacock begonia” (Begonia pavonina), have leaves that shimmer blue because of specialized structures in their epidermal cells.

Peacock begonias are notoriously rare in cultivation: they grow slowly, are fussy about humidity and light, and are difficult to propagate. In an alternate universe, I might be a plant breeder entirely devoted to them, but alas, not in this one.

My Own Blue Discovery

A few years ago, I had one of those moments plant breeders live for. I was checking seedlings from one of my crosses and suddenly froze — the windows on the leaves looked blue. Out loud, to no one in particular, I said: “It’s F’n blue?!”

Certain genetic combinations in Haworthia produce this blue-tinged effect, and I suspect it’s caused by a form of iridescence. I understand the genetics combinations that produce this trait, but I’m keeping the details under wraps for now — maybe one day I’ll publish it.