Held: Wednesday, 5 February 2014

Back to Outline 10 - Side Effects: Images, Output, and More. On to Outline 12 - Raster Graphics and RGB Colors.

Summary

We consider the basics of color theory.

Related Pages

• Reading: Design and Color
• Web resource: A color wheel
• Web resource: A color cylinder
• Web resource: The Color Scheme Designer
• EBoard (Source) (HTML) (PDF)

Overview

• A bit about design.
• A bit about color theory.
• Exploring some images and design spaces.

Administrivia

• No writeup for today!
• Quiz Friday: Documentation, Testing, Side Effects.
• Friday's readings: Raster Graphics, RGB Colors.
• Exam 1 distributed.
• Tomorrow's review session: 9:00 a.m.
  • Sorry for the inconvenience.
  • I'll also try to be around for questions at other times.
• Extra credit:
  • Convocation, Wednesday, 4:15, JRC 101 (Putin and Pussy Riot, Rescheduled)
  • CS Extras, Wednesday at 4:30 in Science 3821: AppDev
  • CS Table, Friday at noon in the Day PDR: NP Completeness

The chief aim of color should be to serve expression as well as possible. Henri Matisse

A Bit About Design

• Many issues to consider, both formal and informal
• Formal attributes include things like balance, symmetry, dimensionality
• Informal goals
  • How does the image lead your eye?
  • Does the image maintain your viewer's interest, or is it easy to see and dismiss.
• Successful designers know how to take advantage of certain formal attributes to acheive various goals (including these informal goals).
• Right now, we're just going to look at some formal issues regarding color.

Basics of Color Theory

• Issue: Do we think in terms of paint (traditional) or in terms of light (computer/theatre)?
• Three models
  • RGB - additive color, based on red, green, and blue lights
    • Adding colors makes things brighter - more light is transmitted
    • Often represented using a 0-255 (integer) or 0-1 (real) range.
  • Red, Yellow, Blue - subtractive color
    • Adding colors makes things darker - more light is absorbed
  • Hue, Saturation, Value
    • Hue is the underlying color
    • Value refers to lightness and darkness (high value is lighter)
    • Saturation refers to how much of the color we have (low saturation is closer to grey, high saturation is purer color)
    • We'll look at the color wheel to ground this understanding
      • A color wheel
      • A color cylinder
      • And we will play with some issues in lab tomorrow
• Working with RYB and the color wheel, we say that there are
  • Three primary colors: Red, Yellow, and Blue
  • Three secondary colors, created by combining the primaries.
  • Six tertiary colors, created by mixing a secondary with the neighboring primaries.
• We also assign temperature to colors: red colors are warmer, blue and green are cooloer
  • Temperature can also affect where in the plane you see something
• The ways you arrange colors affect the way you understand them.
  • Traditionally, there are ranges between harmonious and dischordant.
• Color schemes
  • Complementary - opposite on the color wheel
  • Analagous - three neighboring colors on the 12-color color wheel
  • Monochromatic - variations on one color (different hue/saturation)
  • We may take a quick look at the Color Scheme Designer

Activities

• A few check-ins about HSV.
• Some sample designs, taken from the Kluber version of Digital Design
• Maybe more fun with the Color Scheme Designer