Impossible colors

Via Neatorama I find that Wikipedia has an article on impossible colors. I wonder what Wittgenstein would make of this:

In 1983, Hewitt D. Crane and Thomas P. Piantanida carried out tests using a device that had a field of a vertical red stripe adjacent to a vertical green stripe (or in some cases, yellow–blue). In contrast to apparatus used in simpler tests, the device had the ability to track involuntary eye movement and to adjust mirrors so that the image would appear to be completely stable. The boundary of the red–green stripes was stabilised on the retina of one eye while the other eye was patched and the field outside the stripes was blanked with occluders. This allowed for a mixing of the two colors in the brain, producing neither green for a yellow–blue test, nor brown for a red green test, but new colors entirely. Some of the volunteers for the experiment even reported that afterwards, they could still imagine the new colors for a period of time.

My hunch is that this is one of those reason/cause cases, so that it's possible to tell a story about what might cause our inability to see, say, reddish-green, but that this would pass by the incomprehensibility (grammatical non-existence) of 'reddish-green'. It's also worth noting that the evidence from this experiment is disputed.

My favorite part is this:

In 1927, American horror fiction author H. P. Lovecraft wrote a short story called "The Colour Out of Space" in which a meteorite crashed into a family farm in rural New England. The meteorite contained a mysterious globule of a color that was "almost impossible to describe," with a note that it was "only by analogy" that professors studying the globule called it a color at all.

Incidentally, in the book 90 Minutes in Heaven, which claims to describe what it's like to be dead and then come back to life, the whole heaven part is said to be true only by analogy. There is neither time nor space, we are told, and then follows a lot of stuff about old friends and relatives happily running to greet the dead person, and so on. Curious.

Both cases (Lovecraft's color and a timeless moment that is like a 90 minute meeting with various people) push (or perhaps simply violate) the boundaries of what we (or I) can comprehend. It's probably good to experience a bit of such uncanniness every now and then, but bad to take too much refuge from canny reality in it.