Color is the general term for all hues, including achromatic and chromatic series. Black, white and gray belong to the achromatic series, while red, orange, yellow, green, cyan, blue and purple belong to the chromatic series.
This section briefly introduces hue, lightness, saturation, and color perception. For deeper exploration of color-related knowledge such as color mixing and color models, please refer to specialized literature or online resources.
General Properties of Color
The general properties of color refer to the fundamental variables of color perception distinguishable by human vision. The three attributes of color - hue, lightness, and saturation - are distinct yet interdependent characteristics.
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| Figure: Three Attributes of Color |
- Hue
Hue refers to the intrinsic quality that distinguishes colors. It represents qualitative differences between colors and constitutes the most essential property. The seven spectral colors - red, orange, yellow, green, cyan, blue, and purple - represent typical hues.
Figure: Seven Hues in Spectrum - Lightness
Lightness indicates the brightness level of colors and their reflectivity to light. In achromatic series, white has the highest lightness value while black the lowest, with various grays in between.
Figure: Brightness in Chromatic Series 
Figure: Brightness in Achromatic Series - Saturation
Saturation denotes color purity. Pure colors have maximum saturation, which decreases when mixed with other colors (including black, white, gray or chromatic colors).
Note: Saturation and lightness are distinct concepts. Lightness refers to brightness intensity, while saturation indicates color vividness. High lightness doesn't necessarily imply high saturation.
Color Perception
While colors are physical phenomena without inherent emotion, humans develop psychological responses through accumulated visual experiences. When color stimuli resonate with perceptual memory, they evoke specific emotional reactions.
- Excitement and Calmness
This perception depends on visual stimulation intensity. Hue has the strongest impact, followed by saturation and lightness. Warm colors (red, orange, yellow) stimulate excitement, cool colors (cyan, blue) induce calmness, while green and purple are neutral. High lightness colors appear energetic, low lightness colors serene.
- Temperature Perception
Warm colors: Red, orange, yellow; Cool colors: Cyan, blue; Neutral colors: Green, purple.
Figure: Warm vs Cool Colors - Advance and Recession
Warm colors appear advancing and expansive, while cool colors seem receding and contractive. This spatial perception aids hierarchical content organization in map design.
- Weight and Texture
Color weight relates to perceived density. Darker colors (low lightness) feel heavier, lighter colors (high lightness) appear weightless. At equal lightness, warm high-saturation colors feel heavier than cool low-saturation colors. Weight hierarchy:
- (Heavy) Black > Low lightness > Medium lightness > High lightness > White (Light)
- (Heavy) High saturation > Medium saturation > Low saturation (Light)
Texture perception depends on lightness and saturation: High-lightness grays appear soft, low-lightness pure colors feel hard.
- Luxury and Simplicity
Hue primarily determines this perception, followed by saturation and lightness. Warm vivid colors (red, yellow) appear luxurious, cool muted colors (blue, gray) seem plain. Chromatic colors feel rich, achromatic colors simple.
Figure: Luxury vs Simplicity in Colors - Vivacity and Melancholy
Lightness and saturation influence this perception. Bright high-saturation colors appear lively, dark muted colors seem somber. High-lightness palettes create cheerfulness, low-lightness schemes induce melancholy. In achromatic series: Black/dark gray suggest gloom, white/light gray evoke brightness.
Color Contrast and Harmony
- Color Contrast
- Lightness Contrast
Contrast formed by lightness differences. High-lightness colors appear brighter against dark backgrounds, darker against light backgrounds.
Figure: Lightness Contrast - Hue Contrast
Contrast based on hue differences, including analogous, similar, contrasting, and complementary color comparisons.
Figure: Hue Contrast - Saturation Contrast
Contrast created by purity differences. Identical colors appear more vivid against low-saturation backgrounds and duller against high-saturation backgrounds.
Figure: Saturation Contrast - Temperature Contrast
Contrast between warm and cool colors. The proportion of warm/cool colors determines overall image tone (warm/cool-toned). Temperature contrast enhances visual depth.
Figure: Warm-Cool Contrast - Area Contrast
Contrast achieved through varying color proportions. Spatial distribution of colors affects visual perception - identical hues create different impressions through size and position adjustments.
Figure: Area Contrast
- Lightness Contrast
- Color Harmony
Color harmony involves two concepts: 1) The process of adjusting contrasting colors into cohesive combinations; 2) The rhythmic relationship between hue, lightness and saturation that creates pleasant visual experiences.
While various harmony methods exist, the core principle remains: Color schemes should align with thematic purposes and evoke aesthetic resonance.
Figure: Color Harmony
Related Topics:
Color Design for Point Symbols
Color Design for Area Features