Color Terminology

Basic Terminology

• Color: Often misunderstood; black is a color (not a hue).

Dimensions of Color

• Three Dimensions:

  • Hue: Degree around the color wheel (e.g., green, yellow, red).

  • Saturation: Purity of the stimulus; less saturated colors mix with gray/white (e.g., pink).

  • Brightness: Intensity of light, measured by total energy/potency (photons).

• Brightness vs Lightness:

  • Brightness: Intensity of light sources (e.g., light bulbs).

  • Lightness: Reflectiveness of a surface.

3-D Color Space

• Color Definition: Combination of hue, saturation, and brightness/lightness creates a specific color.

• Conceptual visualization: a sphere where:

  • Hue: Horizontal dimension.

  • Lightness/Brightness: Vertical dimension.

  • Saturation: Distance from the center (gray).

Perception vs Physical Light

• Color Perception: Colors exist in the mind, not as physical properties.

• Light as Electromagnetic Energy:

  • 380 to 740 nm is the visible spectrum.

  • Each wavelength corresponds to different hues (e.g., 400 nm = blue, 580 nm = yellow, 700 nm = red).

• Species Differences: Other animals perceive different wavelengths beyond human vision (e.g., bees see UV; snakes detect IR).

• Perception Construction: Our brains create color experiences (e.g., redness) from wavelengths, not inherent qualities of the electromagnetic energy itself.