Colour mixing

The relevant concept is correcting saturation while preserving value as much as possible. A complementary colour placed opposite the original on the colour wheel can neutralise some intensity, so adding it in a very small amount reduces excessive brightness without radically changing the value. Option D is correct. More white or black changes lightness, and excess water mainly dilutes the paint rather than giving precise saturation control.

The governing concept is reproducibility in colour mixing. A name such as brown or green does not specify the pigment composition, strength, or quantity used. For example, changing the ratio of yellow to blue can produce different greens even when the same names are recorded. Therefore, option A is correct: a useful record should include pigment names, measured proportions, and sometimes the surface or medium. The other options are factually unreasonable.

The governing concept is value: the lightness or darkness of a colour, separate from its temperature or warm-cool character. To make a five-step scale, the student should prepare one stable brown base and alter only measured amounts of white or black. Thus option B is correct. Adding different complements or changing the original pigments can shift the hue and temperature, while increasing red changes the colour bias rather than producing a controlled value scale.

The governing concept is pigment cleanliness and colour bias during mixing. A dull green may result from a contaminated brush, dirty palette, or pigments that already contain a complementary bias. The most reliable first step is therefore option C: repeat the test with clean tools and fresh, known yellow and blue before changing the formula. Black or white changes value, and red can muddy the mixture, so neither diagnoses the original problem.

The governing concept is the interaction between a colour medium and its support. Paper, cloth, wood, or a wall may differ in background colour, texture, and absorbency. An absorbent surface can make paint look lighter or less saturated, while a coloured ground can alter its apparent hue. Thus option D is correct. Brush size, the colour name, and palette drying do not explain why the same mixture looks different on the finished surface.

The governing concept is colour temperature, meaning the warm or cool visual tendency of a mixture. Brown can be warmed by introducing a small, controlled amount of a warm component such as red-orange. Therefore option A is correct. Increasing blue or blue-green would strengthen the cool bias, and increasing black mainly darkens the mixture without reliably correcting its temperature. The addition should be gradual so the brown does not become noticeably red or orange.

The governing concept is hidden hue in a neutral mixture. Grey is often made from several pigments and may contain a slight blue bias that is not obvious by itself. When yellow is added, blue and yellow combine visually or physically toward green, so option B is the likely explanation. Hidden red would tend to push the result warmer, and excess white affects lightness rather than specifically creating green. Yellow is not the relevant complementary explanation here.

The governing concept is complementary colour mixing. Yellow lies opposite violet on the colour wheel, so it can reduce violet’s saturation quickly and may produce a dull grey or muddy result if overused. Option C is correct: add a very small amount, mix thoroughly, observe the change, and repeat only if necessary. Equal quantities are too difficult to control, while refusing to add yellow or adding black first does not directly use the intended complementary correction.

The governing concept is reproducibility: a colour can be recreated reliably only when important variables are controlled and recorded. Option D is correct because guessed quantities and no written record leave no dependable recipe for repeating the mixture. Measured ratios, labels, and clean tools improve consistency, while a dry sample can still provide a useful visual reference even though wet and dry colours may appear somewhat different. The absence of data is the greatest weakness.

The governing concept is controlled visual comparison. If every patch in a colour scale has the same area and similar shape, differences in lightness, darkness, saturation, or hue are easier to attribute to the mixture rather than to patch size. Therefore option A is correct. Equal areas do not make paint dry faster, clean the brush, or change the paper. Uniform samples make the chart more systematic and the progression easier to judge.

The governing concept is complementary contrast and controlled desaturation. Blue-violet is opposite yellow-orange on the colour wheel, so a very small amount can reduce the mixture’s brightness and intensity, creating a muted version. Thus option B is correct. White mainly makes the colour lighter or less saturated without providing the intended complementary neutralisation, while extra yellow or red strengthens the warm colour instead of muting it. The complement must be added sparingly.

The governing concept is controlled tinting: white raises value but can weaken saturation and make a colour look chalky. Adding a small amount of the original base colour restores hue strength and colour identity without making the mixture excessively dark. More white worsens the problem, much black changes the value sharply, and equal complementary colour may neutralise it. Therefore, option C is the practical correction.

The governing concept is proportion control in pigment mixing. Black is a strong modifier, so once too much has been added, recovering the original hue usually requires adding large quantities of other colours. That wastes paint and makes the final shade unpredictable. A fresh mixture allows small, measured additions and clearer comparison. Black cannot simply be removed, and water does not restore a lost hue. Hence option D is correct.

The governing concept is colour perception under illumination. A coloured light source adds its own hue to the reflected light, so the mixture may appear warmer, cooler, darker, or more saturated than it really is. This can lead to an incorrect judgement of both hue and value. Neutral daylight is a better reference; drying and a white palette do not themselves create this lighting shift. Therefore option C is correct.

The governing concept is complementary neutralisation. Yellow is complementary to violet, so a small amount of yellow reduces violet’s saturation and moves it toward a muted grey-violet. White or black can then adjust the value to match the shadow. Adding red strengthens or shifts the hue rather than neutralising it, while the other mixtures do not directly produce the required violet-grey. Hence option A is correct.

The governing concept is complementary neutralisation and the distinction between saturation and value. A tiny amount of green, which is complementary to red, begins cancelling some of red’s chromatic intensity, so saturation decreases first. Such a small addition does not completely replace the hue, greatly raise value, or determine transparency. As more complement is added, the mixture may become increasingly neutral. Thus option B is correct.

The governing concept is complementary colour mixing. Blue and orange lie opposite each other on the colour wheel, so their pigments tend to reduce each other’s chromatic intensity. In balanced amounts, this neutralisation commonly produces a subdued brown or grey rather than a bright secondary hue. The exact appearance depends on the pigments, but green, violet, and pink are not the expected complementary result. Therefore option C is correct.

The governing concept is pigment bias in subtractive colour mixing. A yellow pigment with a slight blue bias contains an unwanted cool component; when it is mixed with violet, the blue influence can become strong enough to push the mixture toward green. Therefore, option A is correct. More red in violet would usually shift the mixture warmer, while white mainly raises value and pure black does not explain the green shift.

In colour theory, value describes lightness or darkness, while saturation describes intensity or vividness. Adding black lowers the value by making a colour darker, and it commonly lowers saturation because the pure hue becomes mixed with a neutral dark pigment. Thus option D is correct. White normally raises value, more pure hue can increase intensity, and water mainly changes transparency or dilution rather than reliably lowering both properties.

The governing concepts are tinting and complementary neutralisation. White first raises the value of blue, making it lighter. Orange is complementary to blue, so a very small amount reduces blue’s saturation without replacing its main hue. The final result is therefore a light, muted blue, making option B correct. Black would darken the colour, while orange does not turn blue into pure green or violet.

Saturation means colour intensity, while value means lightness or darkness. Red is complementary to green, so a small amount of red neutralises part of the green and lowers its saturation. Because only a little is added, the value can remain near medium. Thus option A is best. Much white would raise value substantially, yellow would change the hue, and water mainly changes transparency rather than pigment saturation.

The governing distinction is between physical mixing and optical mixing. When transparent colours are layered, light passes through and reflects back from different layers, so the viewer perceives a combined optical effect without the pigments being fully blended on a palette. Therefore option B is correct. Opaque palette mixing is physical, while black-white mixing and adding white are also direct pigment mixtures.

The governing concept is independent adjustment of hue and value. Since the violet’s value is already correct, adding a small amount of blue with a similar value shifts the hue toward blue-violet while keeping lightness nearly stable. Thus option C is correct. White or black would mainly change value, and yellow would oppose the violet components and may dull or neutralise the mixture.

The governing concepts are colour temperature and value. Blue is generally cooler than yellow-green, so a small amount of blue with a similar lightness can cool the hue while causing relatively little change in value. Thus, option A is best. Black lowers value, white raises value, and red introduces warmth and may also neutralise the green. The blue should be added gradually because a large quantity would overpower the yellow-green and create a different hue.

The governing concept is controlled neutralisation using a near-complementary colour. Blue is opposite the orange component of red-orange, so a very small amount can reduce vividness and mute the colour. Option A is correct because the quantity is limited. A large amount of blue or black can make the mixture muddy or brownish and lower its value sharply; much green can also neutralise the colour unpredictably rather than producing a clean muted red-orange. Add and test the blue gradually.