Color Theory Notes — Fundamentals of Colors I

I – COLOR BASICS

Color is the perceptual attribute of light produced by the spectrum reflected or transmitted to the eye and processed by the brain.
Color can be described by three properties: Hue, Saturation, and Value (Brightness).
- Hue: the actual color name; pure color with no black or white added.
- Saturation: the amount of pure color; more saturation = purer color.
- Value: the brightness; higher value = lighter.
Additional terms:
- Tint: add white to a hue → lighter and less saturated.
- Shade: add black to a hue → darker and more intense.
- Tone: add white and black (or gray) to a hue → less saturated.
Neutrals: Black, Brown, Gray, White; a hue can be neutralized by mixing with its complement.
Color description models:
- Hue, Saturation, Value (HSB). Represented as ext{Color} = (H, S, V).
Color mixing (high level):
- Additive color (light): primaries R, G, B; R+G = Y,\, G+B = C,\, B+R = M,\, R+G+B = W.
- Subtractive color (pigments): primaries often cited as cyan, magenta, yellow (C, M, Y); mixing yields darker tones; painter primaries are often cited as R, Y, B, but perceptual primaries are R, G, B.

Appearance depends on illumination; color results from reflection/absorption of light.
Under white light, colors appear natural; daylight color shifts occur (morning/shade). Incandescent light is warm (more red/yellow); fluorescent/HID lighting can be manipulated to alter color makeup.
White light contains all colors; a balanced RGB content provides good color appearance even if other wavelengths are不足.
The brain partly compensates for color shifts, but changes in light still influence color perception.

Colors evoke emotional and psychological responses; used by artists, interior designers, marketers.
Color psychology informs decision making, mood, and perception; color therapy (chromotherapy) is controversial and not universally supported scientifically.
General associations (cultural context varies):
- Red: energy, danger, passion, power.
- Orange: enthusiasm, stimulation.
- Yellow: joy, intellect, attention.
- Green: nature, safety, growth.
- Blue: trust, calm, intellect.
- Purple: royalty, wisdom, mystery.
- White: purity, safety, cleanliness.
- Black: power, sophistication, mystery.
Colors influence marketing, branding, and environment; meanings can differ across cultures and individuals.

Chevreul — Theory of Opposites (Complementary Contrast):
- Opposite colors on the color wheel intensify when placed near each other and influence surrounding areas.
- Example effect: yellow skin with violet shadows; strong complementary relationships increase chromatic intensity.
Seurat — Harmonics of the Color Circle (Pointillism):
- Harmonies: adjacent, opposite, split compliments, triads, dominant tint.
- Additive color perception on screens; pigments are subtractive.
Cezanne — The Three Dimensions of Color:
- Dimensions: ext{Value}, ext{Hue}, ext{Saturation}.
- Space and form arise from interactions of these dimensions; warm–cool contrast is a function of hue.
- He emphasized that surfaces near the viewer should have the purest color to build form.
Van Gogh — Color and Meaning:
- Analyzed color as expressive; e.g., deep blue with yellow for spiritual aspiration; red/green for human passions.
Birren — A New System of Harmonics:
- Tint = color + white; Tone = color + gray; Shade = color + black.
- Harmonics can be traced by connecting these states with lines; many movements used one of these systems.
The Color Wheel (overview):
- Circles of hues; primaries, secondaries, tertiaries; discusses additive vs subtractive color models.
- Primary debate: Painter’s primaries (C, M, Y) vs perceived primaries (R, G, B); some systems propose four primaries (R, Y, G, B).

A circle of hues joining violet to red; twelve distinct colors are typically used for practical reference.
Primary colors: basic hues that cannot be made by mixing others.
Secondary colors: forming from mixing two primaries.
Tertiary colors: from mixing a primary with an adjacent secondary.
Active vs Passive colors:
- Active colors advance visually when paired with passive hues.
- Warm, saturated, light-value hues are typically active.
- Cool, low-saturation, dark-value hues are typically passive.
Tints are lighter; shades are darker; saturation affects perceived weight.
Some colors are visually neutral or indifferent.

Color Harmony: a balanced, pleasing relationship among colors; the wheel is a guide, not a strict rule.
Palette development relies on hue, value, and chroma.
Common harmonies (start from any hue):
- Monochromatic: variations of a single hue (tints, tones, shades).
- Analogous: three or more colors side-by-side on the wheel.
- Complementary: opposite hues.
- Split-complementary: one hue with the two colors on either side of its complement.
- Double complements: two complementary pairs forming an X.
- Tetrad: four hues equally spaced (square/rectangle).
- Dyad: two colors two steps apart.
- Triad: three colors equally spaced (triangle).
Use harmonies with hue, value, and chroma to develop palettes; color can be a driving or responsive design element.