„You know my tendency is always to imagine things in my head and to work from this idea. I am going to explain my theory of blue, yellow and red, which will probably seem as 'Spanish' to you as my face.
Blue is the male principle, astringent and spiritual. Yellow is the female principle, gentle, gay and spiritual. Red is matter, brutal and heavy and always the color to be opposed and overcome by the other two. For example, if you mix serious, spiritual blue with red, you intensify the blue to unbearable sorrow, and yellow the conciliatory, the complementary color to purple, becomes indispensable... If you mix red and yellow to make orange, you turn passive, feminine yellow into a Fury, with sensual force that again makes cool, spiritual blue indispensable, the man..“

„I barely notice colors unless I taste them. Not the yellows or the greens. I taste the deeper blues. The darker reds.“

—  David Levithan, livro Every You, Every Me

Fonte: Every You, Every Me

„I should like the fields tinged with red, the rivers yellow and the trees painted blue. Nature has no imagination.“

—  Charles Baudelaire French poet 1821 - 1867

„I reduced painting to its logical conclusion and exhibited three canvases: red, blue and yellow. I affirmed: it's all over. Basic colors. Every plane is a plane and there is to be no representation.“

—  Alexander Rodchenko Russian artist and photographer 1891 - 1956

Quote in: 'The Death of Painting'; from the MoMA-website: Interactives: texts https://www.moma.org/interactives/exhibitions/1998/rodchenko/texts/death_of_painting.html
Rodchenko is looking back: in 1921 he executed what were arguably some of the first true monochromes (artworks of one color; source, Wikipedia:Rodchenko)

„My spring has been much better than every travelling springs of the last two years — I have been working — or trying to work my garden into a kind of permanent shape... At the moment I have three rose bushes so full of red and yellow roses that they look on fire — they are really astonishing — You would really laugh to see them — two are very tall — the other smaller — It is a rose that is the reddest red on top and yellow underneath — then sometimes a few spots that are deep butter yellow — and an odd iris — dirty lavender petals reaching up — a pale lavender mixed with yellow that greys it and yellow petals mixed with a little lavender drooping down — very handsome — There are lots of ordinary colors too — many kinds. Well — that's my life“

—  Georgia O'Keeffe American artist 1887 - 1986

In a letter to Anita Pollitzer Abiquiu, New Mexico, (May 31, 1955), from The Complete Correspondence of Georgia O'Keeffe & Anita Pollitzer, ed. Clive Giboire, Touchstone Books, Simon & Schuster Inc., New York, 1990, p. 298
1950 - 1970

„Already in 1915, Sophie Taeuber [his wife] divides the surface of her aquarelle into squares and rectangles which she then juxtaposes horizontally and perpendicularly [as Mondrian, Itten and Paul Klee did in the same period]. She constructs them as if they were masonry work. The colors are luminous, ranging from the raw yellow to deep red or blue.“

—  Hans Arp Alsatian, sculptor, painter, poet and abstract artist 1886 - 1966

Fonte: 1960s, Jours effeuillés: Poèmes, essaies, souvenirs (1966), p. 288, Arp refers in this quote to the structure in the early watercolor paintings by his wife Sophie Taeuber.

„As far as my exhibition concerned [opening was 8 May 1954, in Ghent].... there is however a recent and important painting hanging there 'Man met Boompje' [Man with tree, later titled 'The Gardener] - permettez-moi - with beautiful refracting matters and color: lemon-yellow spots and lacquerish black on white, (face) transparent pure light-blue with a very thin layer glacis over it (in the small wall) and strong-blue painted vertical line. Yellow brown and mauve brush-sweeps with small red dashes over it (for the small tree), and further a lot of beautiful white.“

—  Roger Raveel painter 1921 - 2013

version in original Flemish (citaat van Roger Raveel, in het Vlaams): Wat nu mijn tentoonstelling betreft (opening was 8 mei 1954, in Gent].. .er is echter een recent en belangrijk werk bij n.l. 'Man met boompje' [later 'De Tuinman' getiteld] - permettez-moi- met mooie brekende materies en kleur: citroengele vlekken en lakachtig zwarte op wit, (gezicht) transparante zuivere lichte blauwe met een heel dunne glacis erover (in muurtje) en sterk blauwe geschilderde vertikale lijn. Geelbruine en mauve vegen met daarop kleine rode streepjes (voor boompje) verder veel mooi wit.
Quote of Raveel, in a letter to his friend Hugo Claus, from Machelen aan de Leie, May 1954; as cited in Hugo Claus, Roger Raveel; Brieven 1947 – 1962, ed. Katrien Jacobs, Ludion; Gent Belgium, 2007 - ISBN 978-90-5544-665-0, p. 164 (translation: Fons Heijnsbroek)
1945 - 1960

„Probably every portrait photographer resorts to some such "dodge" for making a face lighter or other similar purpose, and he finds that the application of water-color paint in ever so thin a wash makes so much difference to the printing density that blue is commonly used as being a quick printing color, the effect of which is therefore not so great; an equally dense layer of blue and of red to any portion of a negative would print very differently, the red shutting off the light action much more powerfully than the blue.“

—  Alfred Horsley Hinton British photographer 1863 - 1908

Fonte: Part II : Practical Pictorial Photography, Fidelity to nature and justifiable untruth, p. 20

„Suppose a surface to be part red and part blue; so that every point on it is either red or blue, and of course, no part can be both red and blue. What then, is the color of the surface in the immediate neighborhood of the point. …it follows that the boundary is half red and half blue. In like manner, we find it necessary to hold that consciousness essentially occupies time… Thus, the present is half past and half time to come. …Take another case: the velocity of a particle at any instant of time is its mean velocity during an infinitesimal instant in which that time is consumed. Just so, my immediate feeling is my feeling through an infinitesimal duration containing the present instant.“

—  Charles Sanders Peirce American philosopher, logician, mathematician, and scientist 1839 - 1914

The Law of Mind (1892)

„When I tell her what I’m thinking and she tells me what she’s thinking, our each ideas jumping into the other’s head, like coulouring blue crayon on top of yellow that makes green.“

—  Emma Donoghue, Room

Fonte: Room

„I wish I had the talent to paint the way I feel about you, for my words always feel inadequate. I imagine using red for your passion and pale blue for your kindness; forest green to reflect the depth of your empathy and bright yellow for your unflagging optimism. And still I wonder: can even an artist's palette capture the full range of what you mean to me?“

—  Nicholas Sparks American writer and novelist 1965

Ira Levinson, Chapter 28, p. 326-327
2009, The Longest Ride (2013)

„I can read in red.
I can read in blue.
I can read in pickle color too.“

—  Dr. Seuss American children's writer and illustrator, co-founder of Beginner Books 1904 - 1991

Fonte: I Can Read With My Eyes Shut!

„First: my Friend planted a Row of Indian corn that was Coloured Red and Blue; the rest of the Field being planted with corn of the yellow, which is the most usual color. To the Windward side, this Red and Blue Row, so infected Three or Four whole Rows, as to communicate the same Colour unto them; and part of ye Fifth and some of ye Sixth. But to the Leeward Side, no less than Seven or Eight Rows, had ye same Colour communicated unto them; and some small Impressions were made on those that were yet further off.“

—  Cotton Mather American religious minister and scientific writer 1663 - 1728

As quoted in Zirkle, Conway (1935), The beginnings of plant hybridization p. 105

„Look, the bad guy is the bad guy, I don't care what color he is, when you go to war, if you know the enemy and the enemy dresses in red and you dress in blue, then you shoot at red. … You shoot at the enemy. You try to identify the enemy and the enemy right now, the overwhelming majority of people coming in, are people of color or people of Hispanic origin.“

—  Paul LePage American businessman, Republican Party politician, and the 74th Governor of Maine 1948

In a State House press conference. http://www.pressherald.com/2016/08/26/house-democrats-condemn-lepage-attack-on-westbrook-legislator/ (August 26, 2016)

„I lay under the buckthorn tree. My soul was enchanted. I looked up through its leaves. The sun was coloring them a briljant yellow. They stood out from their delicate red stems, laughing at the sky.
And the sky was deep blue with one small cloud. And the blue was a glorious contrast to the yellow of the leaves. And the wind came and played with them, turning them over so that I could see their shiny upper surfaces. And the wind came down to me, too, bringing me armfuls of sweet fragrance.
The buckthorn was in blossom and that was the prettiest thing about it. Its scenty filled the soft air and covered me in a dream, tenderly, ans sang to my soul a tale of times before I ever was, and of times when I shall be no more..“

—  Paula Modersohn-Becker German artist 1876 - 1907

from her Journal, in Lilleon, June 1898; as quoted in Paula Modersohn-Becker – The Letters and Journals, ed: Günther Busch & Lotten von Reinken; (transl, A. Wensinger & C. Hoey; Taplinger); Publishing Company, New York, 1983, p. 105
1898

„But I've noticed something with other artists who do use the whole range of forms of colours and black - in Albers, for instance, who experiments with yellow, red, blue, the whole scale. Of course I love his colour paintings, but when I see a black-and-white such as 'The Homage to a Black and White Square' [ Josef Albers painted more versions], I like that best, you know. I think it has something to do with deciding just exactly what you really like best. There is always that wonderful element of doubt. I like the black painters really, even if they did work in color.... Velasquez.... also Tintoretto, and Rembrandt... Goya..“

—  Franz Kline American painter 1910 - 1962

Quote of Kline in an interview (March 1960) with David Sylvester, edited for broadcasting by the BBC first published in 'Living Arts', Spring 1963; as cited in Interviews with American Artists, David Sylvester; Chatto & Windus, London 2001, pp. 61-62
1960's

„this blue shirt i have is practically the same color as my jeans, and looking all-blue is something only cookie monster can pull off.“

—  David Levithan, livro Will Grayson, Will Grayson

Fonte: Will Grayson, Will Grayson

„To me the most important thing in composition is disparity. Thus black and white are the strong colors, with a spot of red to mark the other corner of a triangle which is by no means equilateral, isosceles, or right. To vary this still further use yellow, then, later, blue. Anything suggestive of symmetry is decidedly undesirable, except possibly where an approximate symmetry is used in a detail to enhance the inequality with the general scheme.“

—  Alexander Calder American artist 1898 - 1976

1940s, Excerpt, A Propos of Measuring a Mobile (1943)

„pinkish and bluish draperies on neutral grey grounds and black cypresses…… The red of Jeptha's dress…… some reddish brown, some slightly pinkish…… Graduated blue sky…… the ground at the front a grey violet shadow… Look for some turquoise in the blue.(Degas' working note about choosing colors for his future painting 'The Daughter of Jeptha')“

—  Edgar Degas French artist 1834 - 1917

Quote from Degas' working notes; as quoted in The private lives of the Impressionists, Sue Roe, Harpen Collins Publishers, New York 2006, p. 34
quotes, undated

„My mother is convinced that yellow is a happy color and that a happy girl would get a husband.

-Penelope Featherington“

—  Julia Quinn American novelist 1970

Fonte: The Viscount Who Loved Me