1r:1
My dear Theo,
Enclosed a few interesting pages about colour, that is, the great verities in which Delacroix believed.1
Add to this ‘the ancients didn’t start from the line but from the centres’; that is, beginning with the circular or elliptical bases of the masses instead of the outline. I found the right words for the latter in Gigoux’s book, but the thing itself had already occupied me for a long time.2 It seems to me that the more what one does is felt and has life, the more it’s criticized and gives offence, but at the same time it overcomes the criticism in the long run.
What you write to me about Mr Portier certainly pleased me greatly, but the question is whether he sticks to it.3 Only, I know that they do exist, these certainly rather rare people who have collier’s faith4 and aren’t moved hither and thither by public opinion.
That he detected personality in it pleases me very much indeed, and anyway I’m also trying more and more to be myself, remaining relatively indifferent as to whether people think it very ugly or better. That’s not to say that it would be a matter of indifference to me whether Mr Portier sticks to the opinion he has formed — on the contrary, I’ll try to make things that confirm him in it.  1v:2
You’ll receive a couple of copies of a lithograph by this post.5
I’d like to work up the sketch I painted in the cottage,6 with a few changes, into a definitive form of painting.7 And could perhaps be one that Portier could show or that we could send to an exhibition. At least it’s a thing that I’ve felt, and one such that I would be able to point to defects and certain errors in it myself, just as well as other critics.
Yet there’s a certain life in it, and perhaps more than in certain paintings in which there are no errors at all.
I also think that if it had been up to Henri Pille, Le Chat Noir might not have refused it.8
I’m not much bothered about it, anyway, because I want to learn to make lithographs myself so as to be independent.
If I work the sketch up into a painting, I’ll also make a new lithograph of it, and such that the figures — which are now reversed, I’m sorry to say — come right again.
I’m ending now so that the letter doesn’t become too bulky, because Ma’s also going to write.9 More later, and thanks for your letter. With a handshake.

Yours truly,
Vincent

 2r:3
The ancients accepted only three primary colours, yellow, red and blue, and modern painters don’t accept any others. These three colours, in fact, are the only ones that can’t be broken down and are irreducible. The whole world knows that the sun’s rays break down into a series of seven colours, which Newton called primary: violet, indigo, blue, green, yellow, orange and red; but it’s clear that the name ‘primary’ wouldn’t fit three of these colours, which are composite, since orange is made with red and yellow — green with yellow and blue — violet with blue and red. As for indigo, it can’t be counted among the primary colours, either, since it’s no more than a variety of blue. We must therefore acknowledge with Antiquity that in nature there are only three truly elementary colours, which, by being mixed two by two, create three other composite colours, called binaries: orange, green and violet.
These rudiments, developed by modern scholars, have led to the notion of certain laws, which form a luminous theory of colours — a theory that E. Delacroix mastered scientifically and thoroughly, after having instinctively known it.  2v:4 (See Grammaire des arts du dessin, 3rd ed., Renouard).
If one combines two of the primary colours — yellow and red, for example, in order to create a binary colour, orange, this binary colour will attain its maximum brilliance when one places it close to the third primary colour, not used in the mixture. Similarly, if one combines red and blue to produce violet — that binary colour — the violet will be heightened by the immediate proximity of yellow. Lastly, if one combines yellow and blue to form green, this green will be heightened by the immediate proximity of red. Each of the three primary colours is rightly called Complementary in relation to the binary colour that corresponds with it. Thus blue is the complementary of orange, yellow is the complementary of violet, and red the complementary of green. Vice versa, each of the composite colours is the complementary of the primary colour not used in the mixture. This reciprocal heightening is what’s called the law of simultaneous contrast.  2v:5
If the complementary colours are taken at equal value, that’s to say, at the same degree of brightness and light, their juxtaposition will raise both the one and the other to an intensity so violent that human eyes will scarcely be able to bear to look at it. And by a singular phenomenon, these same colours, which are heightened by being juxtaposed, will destroy one another by being mixed. Thus — when one mixes together blue and orange in equal quantities, the orange being no more orange than the blue is blue — the mixing destroys the two tones and the result is an absolutely colourless grey.
But — if one mixes together two complementaries in unequal proportions, they only partially destroy one another, and you’ll have A BROKEN TONE — which will be a variety of grey. That being so, new contrasts will emerge from the juxtaposition of two complementaries, one of which is pure and the other broken. The contest being unequal, one of these two colours triumphs, and the intensity of the dominant one doesn’t prevent there being harmony between the two.  2r:6
Because if one now brings together similar colours in the pure state, but with differing degrees of energy, for example, dark blue and light blue, one will obtain a different effect, in which there will be a contrast by virtue of the difference in intensity, and harmony by virtue of the similarity. Lastly, if two similar colours are juxtaposed, one in the pure state, the other broken — for example, pure blue with grey blue, the result will be another sort of contrast which will be tempered by the analogy between them. One can thus see that there exist several ways, different from each other, but equally infallible, of strengthening, supporting, attenuating or neutralizing the effect of a colour, and they involve working on what’s next to it — by touching what isn’t the colour itself.
In order to heighten and harmonize his colours, he uses the contrast between complementaries and agreement between analogues all together, in other words, the repetition of a vivid tone by the same broken tone.10
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