Chromatics (of Materials)

Chemicals mixed into pigments work by absorbing some light and reflecting the rest.

Color Constancy

In an image employing a limited palette, the gray or neutral areas will take on the appearance of the missing colors.

Chromatics (of Language)

Hue
The color's place in a given color scale.

Saturation
The purity or intensity of the color; the amount of pigment:oil.

Brightness

Shade
The amount of black in the color.

Tint
The amount of white in the color.

Chromatics (of Human Perception)

The retina contains cells called rods & cones.

There are three types of cones:

• S (short-wavelength) ~420nm, violet
• M (middle-wavelength) ~534nm, green
• L (long-wavelength) ~563nm, yellowish green

Colors stimulate each cone type in different proportions—
each color accorded a tristimulus value.
The set of all possible tristimulus values yields the visible color space (10 million colors).

There is one type of rod:
Rods are only informative in dim light,
when the cones are understimulated.

The brain processes tristimulus values into three opponent channels:

• red-green
• blue-yellow
• black-white (luminance)