Maya shrugged. Sax went reading in the material accompanying the chart, to see if they said anything about it. “Ah. It appears that the cones in the retina contain cells sensitive to blue, green or red, and so colors around those three have lots of distinction, while those in between are composites.” Then in the empurpling dusk he came on a sentence that surprised him so much he read it aloud:

“Redness and greenness form another pair which cannot be perceived simultaneously as components of the same color.”

“That’s not true,” Maya said immediately. “That’s just because they’re using a color wheel, and those two are on opposite sides.”

“What do you mean? That there’s more colors than these?”

“Of course. Artists’ colors, theater colors; you put a green spot and a red spot on someone and you get a color all right, and it’s not red or green.”

“But what is it? Does it have a name?”

“I don’t know. Look in an artist’s color wheel.”

And so he did, and so did she. She found it first: “Here. Burnt umber, Indian red, madder alizarin . . . those are all green-red mixes.”

“Interesting! Red-green mixes! Don’t you find that suggestive?”

She gave him a look. “We’re talking about colors here, Sax, not politics.”

“I know, I know. But still. . . .”

“No. Don’t be silly.”

“But don’t you think we need a red-green mix?”

“Politically? There’s a red-green mix already, Sax. That’s the trouble. Free Mars got the Reds on board to stop immigration, that’s why they’re having such success. They’re teaming up and closing down Mars to Earth, and soon after that we’ll be at war with them again. I tell you, I can see it coming. We’re spiraling down into it again.”

“Hmm,” Sax said, sobered. He was not paying attention to solar systemic politics these days, but he knew that Maya, who had a very sharp eye for these things, was getting more and more worried about it— with her usual mordant Mayan dash of satisfaction at the approach of crisis. So that it was perhaps not as bad as she thought. Probably he would have to look into it again soon, pay attention. But meanwhile—

“Look, it’s gone indigo, right over the mountains.” Intense saw edge of black below, purple blue above. . . .

“That’s not indigo, it’s royal blue.”

“But they shouldn’t call it blue if it’s got some red in it.”

“Shouldn’t. Look, marine blue, Prussian blue, king’s blue, they all have red in them.”

“But that color on the horizon isn’t any of those.”

“No, you’re right. Nondescript.”

They marked it on their charts. Ls 24, m-year 91, September 2206; a new color. And so another evening passed.