My girlfriend pointed out to me that my dad and I both cited the colour of the sky after sunset as our favourite colour, although we called it different things. Over at the bone marrow blog, he expressed a desire to “sit there [on the rim of the Grand Canyon] till the darkening sky turns to indigo, my favourite colour, and the first stars appear,” whereas I stated that “My favourite colour is violet – not purple, which seems to be what people think violet is. Violet is the last colour before night-time.” Obviously there’s a misunderstanding here, and my goal is to get to the bottom of it.
I looked up violet on Wikipedia, which reproduced the problem I stated on the About page, that people think violet is purple. Not only does Wikipedia say that the colour was named after the flower, which is obviously purple, but it also lists a number of RGB approximations of violet which are also clearly purple, even to my colour-blind eyes. In fact, the citation from Etymonline clearly says the colour was named after the flower:
c.1330, small plant with purplish-blue flowers, from O.Fr. violette, dim. of viole “violet,” from L. viola, cognate with Gk. ion (see iodine), probably from a pre-I.E. Mediterranean language. The color sense (1370) developed from the flower.
The use of violet as a colour in 1370 that Etymonline reflected the use of the word to denote a cloth pigment with a purplish colour, according to the OED:
1370 Bury Wills (Camden) 5, j violett toga. c1440 Promp. Parv. 509/2 Vialet, yn colowre, violaceus. 1464 Maldon (Essex) Court Rolls Bundle 40, No. 6, ii togas blewe et vyolette, 1 dobelet.
The sense of the word violet that I am referring to as my favourite colour is the spectral colour violet, which is right at the edge of the blue end of the spectrum. I’ve heard it described as “bluer than blue,” which is a description that jives with the fact that violet can’t be reproduced on an RGB monitor, since blue is the bluest colour available on an RGB gamut. The distinction between the spectral colour violet and the shade of purple violet is key to describing my favourite colour, since any approximation of spectral violet using mixtures of red and blue is necessarily going to be purple, not violet.
As to the matter of what indigo is in relation to violet, Wikipedia claims that indigo has been traditionally defined as the colour between blue and violet on the spectrum, although “modern color scientists do not usually recognize indigo as a separate division,” usually lumping it in with violet as a colour with a wavelength of less than 450nm. Since indigo is lumped in with violet, to the point where Wikipedia lists indigo as a shade of violet, it is unfortunately subject to the same conflation with purple that violet is.
Since it would take a spectroscope to determine if the colour after sunset really is violet, or if it’s a mixture of red and blue (or red and violet, for all I know), I would have to say as a disambiguation that my favourite colour is, in fact, the colour at the end of the spectrum, and my brain is simply equating that with the colour of the sky after sunset. Whether or not my dad feels the same way is a matter unresolvable by simple recourse to semantics.