"I do not know how it is with others, but to me the colours of vowels are so strongly marked that I hardly understand their appearing of a different colour, or, what is nearly as bad, colourless to any one. To me they are and always have been, as long as I have known them, of the following tints:--"
A, pure white, and like china in texture.
E, red, not transparent; vermilion, with china-white would represent it.
I, light bright yellow; gamboge.
O, black, but transparent; the colour of deep water seen through thick clear ice.
U, purple.
Y, a dingier colour than I.
"The shorter sounds of the vowels are less vivid and pure in colour. Consonants are almost or quite colourless to me, though there is some blackness about M.
"Some association with U in the words blue and purple may account for that colour, and possibly the E in red may have to do with that also; but I feel as if they were independent of suggestions of the kind.
"My first impulse is to say that the association lies solely in the sound of the vowels, in which connection I certainly feel it the most strongly; but then the thought of the distinct redness of such a [printed or written] word as 'great' shows me that the relation must be visual as well as aural. The meaning of words is so unavoidably associated with the sight of them, that I think this association rather overrides the primitive impression of the colour of the vowels, and the word 'violet' reminds me of its proper colour until I look at the word as a mere collection of letters.