Colors of the Rainbow
Color Properties / Terminology
The Color Wheel
Color Space and Gamut
Color Properties / Terminology
In this section we have a look at the terminology of color
properties and their meaning in different contexts.
Color properties allow us to distinguish and define colors.
The more we know about color properties, the better we can
adjust colors to our needs.
Hue defines pure color in terms of "green", "red" or "magenta".
Hue also defines mixtures of two pure colors like
"red-yellow" (~ "orange"), or "yellow-green" (limitations to
this statement will be addressed later).
Hue is usually one property of three when used to determine a certain color.
Hue is a more technical definition of our color perception which can be used to communicate color ideas.
Hue ranges from 0° to 359° when measured in degrees.
Hues are basic colors we learn to connect with words as children.
Hues can refer to the set of "pure" colors within a color space.
Tint is a color term commonly used by painters.
A tint is a mixing result of an original color to which has been added white.
If you tinted a color, you've been adding white to the original color.
A tint is lighter than the original color.
When used as a dimension of a color space, tint can be the amount of white added to an original color. In such a color space a pure color would be non-tinted.
Other usage / meanings of tint:
* A soft touch or shimmer of a different hue!
* Hair color which doesn't fully cover natural hair color. It adds a touch of color which is supposed to wash out within five to eight weeks.
* Car Window Tint: means of changing the color/transparency of car windows.
Shade is a color term commonly used by painters.
A shade is a mixing result of an original color to which has been added black.
If you shaded a color, you've been adding black to the original color.
A shade is darker than the original color.
When used as a dimension of a color space, shade can be the amount of black added to an original color. In such a color space a pure color would be non-shaded.
Tone is a color term commonly used by painters.
There is a broader and a narrower definition of tone.
The broader definition defines tone as a result of mixing a pure color with any neutral/grayscale color including the two extremes white and black. By this definition all tints and shades are also considered to be tones.
The narrower definition defines tone as a result of mixing a pure color with any grayscale color excluding white and black. By this definition a certain amount of white and black must have been added to the original color. Furthermore the following is true: If you changed the tonal value of a color, you've been adding gray (any ratio of mixture) to the original color.
A tone is softer than the original color.
Tone is not used as a dimension of a color space. Instead, the tonal difference consists of the amounts of white and/or black used to determine a certain color.
Tone as a result of mixing an original color with a hue-scale color (e.g. brownscale / sepia).
Saturation is a color term commonly used by (digital / analog)
Saturation is usually one property of three when used to determine a certain color and measured as percentage value.
Saturation defines a range from pure color (100%) to gray (0%) at a constant lightness level. A pure color is fully saturated.
From a perceptional point of view saturation influences the grade of purity or vividness of a color/image. A desaturated image is said to be dull, less colorful or washed out but can also make the impression of being softer.
We will clear up the term saturation from a color mixing point of view in the color spaces section.
Lightness is a color term commonly used by (digital / analog)
Lightness is usually one property of three when used to determine a certain color and measured as percentage value.
Lightness defines a range from dark (0%) to fully illuminated (100%). Any original hue has the average lightness level of 50%.
A painter might say lightness is the range from fully shaded to fully tinted.
You can lighten or darken a color by changing its lightness value.
Chromatic Signal / Chromaticity / Chroma
This family of color terms is commonly used by (digital / analog)
imaging and video experts.
In the previous section we learned that color perception is a result of achromatic and chromatic signals.
We can therefore define a chromatic signal as the component of color perception that is not achromatic, i.e. any deviation from neutral-color perception (dark, grayscale, illuminated).
The chromatic intensity or chromaticity is the intensity of the chromatic signal contributing to color perception. Chromaticity is similar to saturation since
Chroma is a component of a color model. There's a blue-yellow and a red-green chroma component.
Intensity / Luminosity / Luma
In general, intensity is a synonym for magnitude, degree
or strength. It can therefore be used in conjunction
with any color property. Nevertheless, it carries special
meaning in certain contexts.
For painters the meaning of intensity is equivalent to the meaning of saturation.
For physicists intensity refers to different aspects of radiation.
When speaking of light, the intensity can mean the number of photons a light source emits.
The following sources provide a deeper insight:
- Luminosity Function
Luma (%) is the intensity of the achromatic signal contributing to our color perception.
Brightness / (relative) Luminance
Brightness is an attribute of our perception which is
mainly influenced by a color's lightness. This is probably
why brightness and lightness are often mixed up.
Brightness is not a color property, if used "correctly".
For one color of specific hue the perception of brightness is also more intense, if we increase saturation. A higher level of saturation makes a color look brighter.
In relation to other colors the brightness intensity of a color is also influenced by its hue. We can then speak of (relative) luminance to refer to brightness.
It's very important to know more about luminance.
A grayscale is a series of neutral colors, ranging from black
to white, or the other way around. Each step's color value
is usually shifted by constant amounts.
A grayscale color can be determined by a value of a one-dimensional color space:
On a white surface (e.g. paper) the grayscale color's value equals to the relative intensity of black (ink) applied to the medium.
On a black surface (e.g. monitor) the grayscale color's value equals to the relative intensity of white (light) applied to the medium.