Monday is St. Patrick's Day.
"Something that may make us suspicious," whispers the 20th-Century philosopher Ludwig Wittgenstein, "is that some people have thought they recognized three prima ry colors, some four."
Yellow, yes, by its very hysteria. Less voluble but more profoundly insistent, red too is a primary, irreducible. And stoic blue.
But green? The suspicion. The mystery .
For hundreds of years its purity has been debated, and is debated still. The physicist Isaac Newton counted green among "the seven principal colors," a gracious notion embracing as well the seven spheres, or discernible planets, and the seven notes of the diatonic scale. Then J. C. Le Blon, the reductionist, saw only red, blue, yellow, and soon the poet Johann Wolfgang von Goethe declared blue and yellow alone! (Here Hermann Ludwig Ferdinand von Helmholtz, the scientist, leaped in with his theory of red-blue-green, but he confused the issue and referred not to pigments but to light rays.) And in this century the artist Josef Albers simply waffled, citing red-blue-yellow as the primaries of the colorist, three primaries for the physicist (not including yellow) and four for the psychologist (including green), "plus two neutrals, white and black."
The mystery holds.
Skirting suspicion, some quantify the color and list isolated facts: Of the 8 to 10 million hues distinguishable by the human eye, the greatest range distinguishable are the various greens. In the spectrum of light, true green vibrates at 512 to 530 millimicrons. The Tiv of Nigeria recognize no green among their colors, only dark, light and reddish. In Asia, green is regarded as a sign of disease.
Others grope toward emotional truths: The green of Max Luscher's color test, developed by the psychologist as a diagnostic tool, is said to represent "an expression of firmness, of constancy and, above all, resistance to change. . . . Its sensory perception is astringence, its emotional content is pride." Wassily Kandinsky, the painter, wrote of the "complete quietude and immobility" in absolute green, "which is the most restful color in existence, moves in no direction, has no corresponding appeal, such as joy, sorrow, or passion, demands nothing."
Yet others find in green a game of wits: "The bard's noserag," Buck Mulligan calls Stephen Dedalus' handkerchief in James Joyce's "Ulysses." "A new art colour for our Irish poets: snotgreen." Snotgreen is not listed in the National Bureau of Standards' "Color: Universal Language and Dictionary of Names," a great semantic puzzle, but these are: Shamrock (Strong Yellowish Green), Blarney (Vivid Green) and Erin (Moderate Green). American Green is categorized as Grayish.
And still the mystery.
A primary? Today I say yes: There was a traffic signal, brilliant green, suspended in damp gray daylight, pure. It could not have been mixed from any other colors.
Wittgenstein agrees: "If you call green an intermediary color between blue and yellow, then you must also be able to say, for example, what a slightly bluish yellow is, or an only somewhat yellowish blue. And to me these expressions don't mean anything at all."
But what of bitter teal, yanked up from the depths of indigo to gasp at the surface? What of the maddening chartreuse?
And I also say: I remember a traffic signal glowing blue, the yellow sucked from it by a quirk of light, the light of high sun filtered through smoke.