Colour mixing

Correct answer: B. The gamut of traditional pigments does not reach pure cyan

Explanation: The governing concept is the limited gamut of subtractive pigments. A pigment absorbs selected wavelengths and reflects the rest; ordinary red, yellow and blue paints do not provide the spectral combination needed for a highly saturated, pure cyan. Mixing them usually absorbs more light and produces a duller result. Thus B is correct. Black darkens a colour, red plus yellow makes orange, and blue does not reflect all light.

Correct answer: B. A slightly subdued or muddy orange

Explanation: Red mixed with yellow first produces an orange family colour. Adding a small amount of blue introduces a component opposing orange on the colour wheel, so the mixture loses some saturation and tends toward a duller, muted or muddy orange. It will not become pure green or pure violet because the proportions are dominated by red and yellow, and the added blue is only a small amount. The result can vary with pigment properties.

Correct answer: A. The pigments had opposing colour biases or contamination

Explanation: In an ideal traditional mixing exercise, red and blue can produce violet. However, real pigments are not perfectly pure: a red may lean toward yellow and a blue may contain a greenish or other unwanted bias. Such opposing undertones, or contamination from an unclean brush or palette, introduce extra wavelengths and reduce saturation, making the violet muddy. A large palette or white surface does not normally cause this result.

Correct answer: B. Bluish red and reddish blue

Explanation: The governing concept is colour bias in subtractive pigment mixing. To obtain a clean violet, choose a red that leans toward violet and a blue that also leans toward violet. Their unwanted yellow or green influences are limited, so the mixture remains brighter. Therefore option B is correct. Yellowish red and greenish blue introduce opposing biases and can make a duller, less saturated mixture.

Correct answer: B. Green-biased yellow and green-biased blue

Explanation: The governing concept is selective pigment mixing. A bright green is produced when both starting colours lean toward green: the yellow should be green-biased and the blue should also be green-biased. This minimises unwanted red, which would neutralise the mixture. Thus option B is correct. Orange-biased yellow, violet-biased blue, and red-influenced colours add complementary contamination and make the green duller; red and blue do not target green.

Correct answer: B. Adding white and a small amount of complementary colour

Explanation: The governing concept is the distinction between value and saturation. Value describes lightness or darkness, while saturation describes colour intensity. White raises the value by making the colour lighter; a small amount of its complementary colour lowers saturation by neutralising it. Therefore option B changes both properties. A repeated layer mainly changes coverage, water may alter transparency, and spreading alone does not deliberately alter both value and saturation.

Correct answer: A. Yellow to yellow-orange to orange to red-orange

Explanation: The governing concept is proportional pigment mixing on the warm side of the colour wheel. Starting with mostly yellow gives yellow; gradually adding red first produces yellow-orange, then a balanced orange, and finally red-orange as red becomes dominant. Therefore option A correctly follows the changing ratio. The other progressions require colours not produced by increasing red in a yellow mixture, so they do not represent the stated process.

Correct answer: B. More clean yellow and less clean blue

Explanation: The governing concept is controlling hue and saturation through the proportion and cleanliness of pigments. Yellow-green becomes brighter when a clean, vivid yellow is dominant and a smaller amount of clean blue shifts it toward green. Option B is correct. Muted pigments reduce brightness, equal green and red tend to neutralise each other, and yellow with violet introduces a complementary relationship that can make the mixture dull or brownish rather than bright yellow-green.

Correct answer: C. A yellow contamination or bias in the red or blue

Explanation: The governing concept is complementary-colour neutralisation. Yellow is complementary to violet, so a red or blue pigment with a yellow bias introduces an unwanted near-complement into the mixture. That contamination reduces saturation and makes the violet look muddy. Equal quantities do not guarantee purity, while white paper and a clean palette do not create this pigment contamination. Therefore, option C is correct.

Correct answer: D. Bluish red and reddish blue

Explanation: The governing concept is pigment bias in subtractive colour mixing. A blue-violet needs red and blue pigments that lean toward each other: the red should be bluish and the blue should be reddish. This minimises yellow or green contamination, so less complementary absorption dulls the result. Yellowish red and greenish blue introduce unwanted biases, while the other mixtures do not directly form a clean blue-violet. Thus option D is correct.

Correct answer: A. A very small amount of red

Explanation: The governing concept is controlled complementary mixing. Red is complementary to green, so a very small addition of red reduces green’s saturation and makes it more natural, subdued, and suitable for foliage. The amount must be added gradually because too much red can push the mixture toward brown or neutral. White mainly creates a tint, while extra blue or yellow changes the hue rather than gently muting it. Therefore option A is correct.

Correct answer: B. Orange

Explanation: The governing concept is colour temperature controlled by mixture proportion. Blue contributes a cool bias, whereas orange contributes a warm bias. If the neutral mixture appears too cool, increasing orange gradually counterbalances the blue and moves the mixture toward a warmer neutral. Adding more blue would intensify the problem; black changes value and white creates a lighter tint rather than correcting temperature. Hence option B is correct.

Correct answer: C. When a light tint of a deep saturated colour is made

Explanation: The governing concept is the difference between value and saturation. Adding white raises a colour’s value, meaning it appears lighter, and when it is mixed into a deep saturated pigment it also reduces the colour’s visual intensity by diluting it. This creates a tint. An already grey colour has little saturation to lose, while water alone and removing black do not describe the same mixing process. Therefore option C is correct.

Correct answer: D. Add very small amounts of black gradually

Explanation: The governing concept is controlled value adjustment. Black lowers a colour’s value, or darkness level, but adding it in very small amounts and checking after each addition helps preserve the original hue as far as possible. A large amount of black can overpower the hue, while complementary or three-colour mixtures strongly neutralise and alter it. Therefore gradual, sparing addition of black in option D is the best method.

Correct answer: A. Gradually reduce yellow-orange and increase blue in warm grey

Explanation: The governing concept is colour temperature progression within neutrals. Yellow-orange gives a warm bias, while blue gives a cool bias. Therefore, reducing the warm component and gradually increasing the blue component moves each successive grey from warm toward cool without merely changing its lightness. Keeping grey identical creates no progression; changing only black or white changes value, not temperature. Thus option A is correct.

Correct answer: B. Yellowish red and reddish yellow

Explanation: The governing concept is pigment bias and minimising complementary contamination. To obtain a bright orange, choose a red and yellow that both lean toward orange: a yellowish red and a reddish yellow. Their mixture contains less unwanted blue or violet influence, so it retains greater saturation. Bluish red and greenish yellow introduce opposing biases, red and blue make violet, and yellow with violet tends to neutralise. Hence option B is correct.

Correct answer: C. Green first becomes muted and then moves toward brown-neutral

Explanation: The governing concept is complementary neutralisation. Red is complementary to green, so a small and gradually increasing amount first reduces green’s saturation and makes it look muted. As more red is added, the mixture moves farther from pure green toward a brown or neutral appearance because the opposing colour components absorb one another. It does not become brighter, blue, or white. Therefore option C is correct.

Correct answer: D. Add white gradually

Explanation: The governing concept is separating value from colour temperature. Because the brown’s temperature is already correct, the correction should target only its value, or lightness. Adding white gradually raises the value while usually preserving the warm-cool balance better than adding a coloured pigment. Yellow, blue, or red would shift the temperature and hue, so they do not solve the stated problem as precisely. Therefore option D is correct.

Correct answer: A. It may become lighter than desired and be difficult to darken accurately

Explanation: The governing concept is gradual value control in colour mixing. White raises the value of blue, so adding a large quantity at once may make the mixture much lighter than intended. Darkening it accurately afterward requires adding blue in small amounts and can disturb the original hue. Therefore option A is correct; white does not automatically turn blue green, instant drying is not the issue, and a palette does not change the colour by itself.

Correct answer: B. Add a very small amount of green

Explanation: The governing concept is complementary colour neutralisation. Green is opposite red on the colour wheel, so a very small amount can reduce red’s intensity and make it muted. Because the quantity is small, the value changes less than it would with a large amount of white or black. Thus B is correct. White makes a tint, black makes a shade, and extra yellow shifts the hue toward orange rather than simply muting it.

Correct answer: C. Pigments may have different red or green biases

Explanation: The governing concept is pigment bias, sometimes called a colour temperature tendency. Two paints labelled blue may contain different pigments: one can lean slightly toward red and another toward green. When each is mixed with red, those hidden biases affect the cleanliness and appearance of the violet. Therefore C is the best answer. Value differences may matter in appearance, but palette size and brush length do not explain the pigment interaction.

Correct answer: D. One colour may contain a blue or green contaminating bias

Explanation: The governing concept is pigment purity and unwanted complementary bias. Red and yellow should normally produce orange, but a red or yellow containing a slight blue or green tendency can introduce a complementary component. That component reduces saturation, making the orange dull even when the proportions are equal. Therefore D is correct. Equal proportions are not automatically wrong, orange need not be premixed, and white is not required to create orange.

Correct answer: A. Place the base colour in the centre and gradually increase white on one side and black on the other

Explanation: The governing concept is a value scale built from one hue. Place the base colour in the centre, then add progressively more white to create lighter tints on one side and progressively more black to create darker shades on the other. This keeps the hue under study consistent while changing value systematically. Therefore A is correct; complementary colour changes intensity, water changes dilution, and different hues prevent a controlled comparison.

Correct answer: B. Add a very small amount of green

Explanation: The governing concept is targeted hue correction with a complementary colour. Green is complementary to red, so adding it in a very small amount can neutralise the excess red in the brown. The small quantity helps preserve the already-correct value, although the mixture should be tested gradually. Thus B is correct. White would raise value, black would lower value, and more red would increase the unwanted bias.

Correct answer: C. Add a very small amount of red-violet

Explanation: The governing concept is reducing saturation without unnecessarily changing hue or value. Red-violet lies opposite yellow-green on the colour wheel, so a very small amount can neutralise some of its intensity and make it less bright. Therefore C is correct. Adding yellow or blue shifts the hue, while adding white generally creates a lighter tint rather than a controlled reduction of chromatic intensity.