Wiki quote: Classification as a spectral color
Indigo was defined as a spectral color by Sir Isaac Newton when he divided up the optical spectrum, which has a continuum of wavelengths. He specifically named seven colors primarily to match the seven notes of a western major scale,[5] because he believed sound and light were physically similar, and also to link colors with the days of the week,[citation needed] and other lists that had seven items. The human eye is relatively insensitive to hue changes in the wavelengths between blue and violet, where Newton defined indigo to be; most individuals do not distinguish indigo from blue and violet. For this reason, some commentators, including Isaac Asimov,[citation needed] hold that indigo should not be regarded as a color in its own right, but merely as a hue of blue or violet. Color scientists typically divide the spectrum at about 450 nm between violet and blue, with no indigo.[2][6] Others continue to accept it,[7] as it has been accepted traditionally as one of Newton's named colors of the spectrum along with red, orange, yellow, green, blue, and violet. Patty (1) Indigo does seem to be a "true" blue (i.e. not greenish or purplish). So how id the word "indigo" come to be applied to the shade between blue and violet in he rainbow? (At least the way I learned it: red, orange, yellow, green, blue, ndigo, violet) As to this question, it seems to be Sir Isaac Newton who so named the colors of the spectrum--violet, indigo, blue, green, yellow, orange, red. So one has to wonder what his standard was for "true blue." Ann Wass _______________________________________________ h-costume mailing list h-costume@mail.indra.com http://mail.indra.com/mailman/listinfo/h-costume
