In the depth of winter in Alaska one thinks a good deal about light. There's plenty of darkness to think about it in. Cranking along on the WSC, it suddenly struck me that much as I adore seeing the subtle colors of this thing as it develops, it's easy to work on because there are only two strands in each row, Light and Dark. And as long as you can keep your eesit for this row distinct from the ball of cream for that row, it's 3 lights, 1 dark, 1 light, 1 dark, 5 lights and no bother as long as you've got the right yarn balls for the right rows.
Now, the Shetland Islands and Fair Isle, where this brand of knitting was concocted or perfected, is on a similar lattitude to Alaska. And for sure it was developed in a world that was lit only by fire, right? In wintertime knitters were sitting by a peat-burning fireplace, an oil or a kerosene lamp. Less light even than all the bulbs and tubes burning in my house. (And I still can't see the colors properly except in daylight.)
Here comes the Blinding Insight, which I'm sure has occurred to you by now, too: The majority of knitting time would have been in the winter when there were fewer outdoor chores to do. Wouldn't it have been a natural thing to limit your colorwork to two per row, a Dark and a Light, so that you could carry on without daylight and have fewer chances for mistakes?
This idea is suddenly so totally obvious that I don't want to check knitting histories to find out who has already thought of it. I don't care. It came to me independently, as it did to the first fair isle knitters (probably), and I like to feel a kinship with them as they sat before the fire, chatting, telling and hearing stories, or singing, and I sit before the dvd film with an electric lamp on my work, while we all create a dance of color in wool.
PS: Scandinavian knitting. Two colors, dark and light. Think about it.
PPS: I'm now halfway through the second pattern repeat!