Above them, the burning brilliance of a star gave strange glow and color to the crystal pylons. What color was the star? He turned to Meta, irritated at his inability to be sure.Marion Zimmer Bradley is probably best known as a fantasy writer. Her most familiar works are the The Mists of Avalon, a retelling of the Arthurian legends from the perspective of the female characters, and her novels set on the mythical planet Darkover, which has a feudal sword-and-sorcery type of society.
"Meta, what color is this sun? I've been all around the spectrum, and it's not red, blue, green, orange, violet—" He broke off, realizing what he had said and what he had seen. "An eighth color," he finished, anticlimatically.
"You and your talk of colors," Ringg grumbled, "I wish I knew what you Mentorians see! It's like trying to imagine seeing a smell or hearing light!"
Meta laughed. "As far as I know, no one's named it. Sometimes we Mentorians call it catalyst color. I think only Mentorians can see it as separate color."
~ The Colors of Space by Marion Zimmer Bradley
One of her earliest novels, however, is a science fiction space opera. The Colors of Space, originally published in 1963, is the story of Bart Steele, a recent space-academy graduate. Bart has a unique set of eyes: his mother is from the planet Mentor, where humans have been engineered to tolerate very bright lights. On top of that, he can see a wider range of light wavelengths than most other humans. Bart has the ability to see a mysterious "8th color", which he is unable to name.
It was Isaac Newton who split the visible light spectrum into seven colors - red, orange, yellow, green, blue, indigo and violet. However, those divisions are fairly arbitrary, and human eyes can actually distinguish many more than seven colors. The three different types of light-detecting cone cells in the retina allows an average person to distinguish 1 million colors. A small percentage of women may have four different types of cone cells which allows them to distinguish as many as 100 million different colors. It's not clear what Bart is actually able to see, but I like to think that he can see into the ultraviolet, like a bird or a lizard.
In any case, Bart's special visual ability takes him on an adventure through the galaxy. It's a juvenile, so it's an easy and entertaining read. And even better, it's free:
Image: 1 million colors in the human visible range - click for full size image.
Tags:science fiction, biology