Unit
- Hue: The spectral identity of a color (red, green, blue, etc.). Hue is the attribute we name when describing a color, and it is measured in degrees on a color wheel ranging from 0 to 360.
- Saturation: The intensity or purity of a hue. A fully saturated color contains no gray, while desaturated colors appear washed out. Saturation is a percentage from 0 (gray) to 100 (pure hue).
- Luminance: The perceived brightness of a color. Luminance is independent of hue and saturation, and it is critical for establishing contrast in an image. In digital grading, luminance is often adjusted via a lift-gamma-gain system.
- Primary colors: Red, green, and blue are the additive primaries used in digital displays. Mixing them at full intensity produces white. Yellow, cyan, and magenta are subtractive primaries used in printing.
- Secondary and tertiary colors: Secondary colors (yellow, cyan, magenta) result from mixing two primaries. Tertiary colors are intermediate hues such as yellow-green or blue-violet. These relationships form the basis of color wheel organization.
- Complementary colors: Colors opposite each other on the wheel (e.g., red and cyan). When placed side by side, they create strong contrast and visual tension. In grading, complementary relationships are used for color balance and creative look creation.
- Analogous colors: Colors adjacent on the wheel (e.g., blue, blue-green, green). They produce harmonious, low-contrast palettes often used for natural scenes or calming moods. Analogous schemes are common in landscape grading.
- Triadic colors: Three evenly spaced colors on the wheel (e.g., red, yellow, blue). Triadic schemes offer active yet balanced palettes. Graders often employ triadic adjustments to add depth without causing color casts.
- Color Temperature: Measured in Kelvin, describes the warmth or coolness of light sources. In grading, adjusting color temperature allows matching shots from different lighting conditions or creating mood. Warmer temperatures (lower Kelvin) appear orange, while cooler temperatures (higher Kelvin) appear blue.
- White Balance: The process of neutralizing color casts so that whites appear neutral. Graders use white balance to ensure consistent color across scenes. In digital grading, white balance is typically adjusted by fine-tuning the gain of each RGB channel.
- Color Space: The specific range of colors reproducible in a system, such as Rec. 709 for HD video or DCI-P3 for cinema. Understanding color space is crucial for ensuring accurate color reproduction across different displays and delivery formats.
- Gamma: A nonlinear encoding function that adjusts luminance to match human vision. Gamma correction preserves shadow and highlight detail. In grading, gamma adjustments affect overall contrast and are applied via lift, gamma, gain controls.
Design Principle
Principle: Color Harmony through Wheel Relationships
Definition: Color harmony is the visual balance achieved by selecting colors according to established patterns on the color wheel. The three primary harmonies are complementary, analogous, and triadic. Each produces a different visual effect: complementary for contrast, analogous for unity, triadic for variety.
Application: When grading a dialogue scene, the grader may choose an analogous palette of warm oranges and yellows to create intimacy. For an action sequence, complementary blue-orange contrast can heighten visual impact. The color wheel is the foundational tool for making these decisions systematically.
Quick Revision
- Hue, saturation, and luminance are the three attributes of color that graders manipulate.
- Primary colors (RGB) are additive; secondary colors (CMY) are subtractive.
- Complementary colors create high contrast; analogous colors create harmony.
- Triadic schemes provide balanced vibrancy when evenly spaced on the wheel.