In both theoretical and practical terms, color and its perception are central to all figurative arts, from painting right through to cinema. The principles of color theory are indispensable in any audiovisual project, since they form the very basis of what we create when we shoot, photograph or light a scene. First of all, color and color perception are two interrelated yet quite distinct aspects.
The perception of color depends heavily on the human eye, and the brain’s interpretation of its signals. If we think of green, for example, each of us will form in our minds a different idea of green, which is thus an approximation of the color, a personal interpretation of it. This is a consequence of our ability to adapt to different lighting conditions in order to see the same color at different times of the day. Film and digital media cannot boast the same interpretive power, and so color theory must be carefully applied if we want colors to correspond with the reality we perceive.
Not only this, but perception does not allow us to identify colors according to absolute values that we can match to modern measurement and cataloging systems, but changes according to the chromatic range of individual colors. It is therefore important to know how a combination of colors can affect the viewing of an image. In all four examples below, the central rectangles are colored with exactly the same red, yet to our eye they look quite different. What should appear as identical colors trigger different perceptions depending on their combination with another color. In rectangle 2, for example, the eye struggles to perceive the outline of the red rectangle on the magenta background, because it tends to privilege color over shape.
How, then, can we define the color of light beyond any variations in perception? Well, its absolute value, unaffected by external factors, can be established using three fundamental parameters:
Every object has a certain hue, which we can define as that characteristic of the object itself to reflect a certain frequency or range of frequencies, making us perceive a given color.
The apple reflects different frequencies at different points
In the example of the apple in the image above, green is reflected differently at different points on its surface. We know that it is the same green, but, based on the incidence of light, the object reflects colors that, if considered separately, are very different. Point 1 has a clearly green hue, point 3 has a white hue, while the stalk, by its own nature, has a different color altogether.
Brightness represents the transition of a color through all its shades from black to white. It is independent of hue, as we may have both a light shade of green and a dark shade of green of exactly the same hue, with the perception of brightness changing while the perception of hue does not.
Three shades of red in decreasing brightness
The red in all 3 cases is still red.
- Bordeaux (red with less brightness)
- Red that is almost black (red almost without any brightness at all)
Saturation is how we measure the ‘purity’ of a color in relation to its white component, affecting how vivid or dull it appears at the same light intensity, with a zero-saturated color appearing totally white. Generally, direct light makes colors appear highly saturated, while reflected light appears duller. This effect is most noticeable in a studio with lights pointed directly onto the subject.
Color identification systems
Using the parameters we have briefly described, various color identification systems have been developed, among which:
- The Munsell Color System
- The Additive Color Wheel (RGB)
- The Subtractive Color Wheel (YRB)
This system takes into account five primary colors, red, yellow, green, blue and purple.
Left: the primary colors of the Munsell System. Right: a color wheel.
This system is mainly used in printing and uses colors that have a precise brightness and saturation. Brightness ranges from 0 to 100, where 0 represents black and 100 represents white, while saturation ranges from 0 to 16, where 0 represents neutral gray and 16 represents the hue at its maximum expression, or ‘chroma’.
Additive and subtractive color wheels
The Red-Green-Blue (RGB) Additive Color Wheel is based on the phenomenon that if you sum several lights sources with complementary colors you obtain white light. The Red-Yellow-Blue (RYB), or Cyan-Magenta-Yellow (CMY), Subtractive Color Wheel is used in painting, since complementary colored pigments mixed together make black.
1. Additive colors used in photography and cinematography
2. Subtractive colors used in painting
Given the importance of lighting, photography and cinematography use the additive wheel as a reference system.
Hot and cool colors
A common distinction is made between warm and cold colors, the product of a perception of certain chromatic ranges. The main warm colors are yellow, orange and red, while cold colors include blue, green and violet. However we should not our limit our discussion to temperature alone. Some cold colors can suggest calm and serenity, such as the bright green of a forest or the blue of the sky. On the other hand, yellow or orange can remind us of the sun or fire, and may give us a feeling of warmth with a stimulating and not necessarily relaxing effect.
Such considerations clearly constitute a further factor to take into consideration in photographic and video lighting. A color wheel, in this regard, is an excellent tool for assessing a scene during lighting tests. Today, you can easily download a color wheel app on any smartphone. Adobe Kuler, now incorporated in the App Store and Play Store ‘Adobe Capture CC’ app, for example, is impressive software that provides all possible combinations of complementary, analogous, monochromatic and compound colors, and so on.
1. A 12-color system with the primary colors red, orange, yellow, green, blue and indigo, plus 6 intermediate colors
2. The absolute primaries: blue, red and yellow
Colors and distances
Another phenomenon that should not be overlooked is the perception of distance according to the brightness of different colors. Even when working in black and white, and thus various shades of gray, lighter objects in a scene tend to appear closer to the viewer, while darker objects tend to appear farther away. The same principle applies to color in general, though we must also consider the hue of the various colors, in addition to their brightness.
1. ‘Warm’ colors appear closer to the viewer.
2. ‘Cool’ colors appear farther away.
As shown in the image above, warm colors appear closer and cool colors appear farther away from the viewer, and when a warm color appears next to a cold color, the perception of distance is accentuated. The phenomenon is even more evident if you play with brightness and hue at the same time, leveraging warm and cool and light and dark to obtain the maximum perception of distance, matching a warm, bright color against a cool, dark color.
The symbolic value of color
All colors influence us in different ways, both at conscious and unconscious levels, due to symbolic connotations. Such connotations are not necessarily universal, though some ancestral associations are common. Below, for example, is a list of some of the most commonly widespread associations in western culture:
- Red: love, blood, danger, passion
- Orange: intensity, reflection, life
- Yellow: the sun, flames, a good mood, joy, warmth
- Green: relaxation, nature, balance, rebirth
- Blue: serenity, peace, cold
- Purple: mourning, mysticism, royalty
The culture of belonging, in general, plays a decisive role in the suggestive power of a color. In many western countries, for example, white is widely used in weddings to dress the bride, but, in some areas of the Far East, the color is more likely associated with death and funeral rites.