5) Specifying Colors II

📖 About

Last time we learned about the Trichromatic theory for color vision, and the associated RGB color model and its cubic geometric representation. While the RGB model has very interesting mathematical properties, it does not provide a natural/intuitive way to think about color.

In this unit, we discuss another theory for color vision: the so-called Color-Opponent theory. This alternative framework was originally proposed by Karl Ewald Hering in 1892, based on evidence from color-adaptation experiments and the linguistic observation of certain color names.

The opponent-color theory suggests that the way we perceive color is controlled by 3 opposing systems (or channels) in our vision:

  • Red-Green
  • Blue-Yellow
  • Black-White

Interestingly, the color models associated with the opponent-color theory have a cylindrical geometry instead of the cubic space of RGB.

More important, the main practical tools that emanate from this color theory are 1) the famous color wheel, and 2) the color-picker devices.


🎯 Objectives

At the end of this unit you will be able to:

  • Explain the Color-Opponent theory of color vision.

  • Describe what color models are typically used in color-picker tools.

  • Explain the color wheel.

  • Name at least three different color schemes derived from the color wheel, and what characterizes them.


🌠 Slides

Opponent-Color Theory (google slides)

Cylindric Color Modelx (google slides)


💻 Code

TBA


📖 Assignment

TBA