Understanding Color and Light

What is Color?

• Color is light that interacts with objects.
• When light hits an object (like a banana), it reflects certain wavelengths to our eyes.
• The color we perceive depends on which wavelengths are reflected and which are absorbed.

Light and Its Spectrum

• Isaac Newton used a prism to split white light into seven colors, demonstrating that colors are different wavelengths of light.
• Each color has a different wavelength, and the combination of these wavelengths produces various colors.

Pigments and Color Perception

• Objects contain pigments that absorb certain wavelengths and reflect others.
• Bananas reflect yellow light while absorbing other wavelengths.
• Pigments can be common (green in plants) or rare (ultramarine from gems).

Color Mixing

• Mixing colors involves understanding which wavelengths are absorbed and reflected.
• Primary colors for mixing pigments: Red, Yellow, Blue.
• Our eyes perceive colors based on the wavelengths hitting our cone cells in the retina.
• Three types of cone cells:
  • S cone: Short wavelengths (blue)
  • M cone: Medium wavelengths (green)
  • L cone: Long wavelengths (red)

Color Perception and Brain Interpretation

• Our eyes work with RGB (Red, Green, Blue) for color perception, not RYB.
• Invisible colors (like pink) result from the brain's interpretation of signals from cone cells.
• Each person's eyes may have different sensitivities, leading to color blindness.

Historical Perspectives on Color

• Artist Johann Wolfgang von Goethe (Tainter's view) argued that color is subjective, suggesting Newton's theories were incomplete.
• Color harmony has been used in art and design for centuries.

Development of Color Photography

• Early photography was monochromatic; color was added manually with dyes.
• James Clerk Maxwell proposed capturing scenes using RGB filters to recreate colors.
• First colored image achieved using this method.

Color Mixing Methods

• Subtractive Color Mixing: Used in art, where colors absorb certain wavelengths.
• Additive Color Mixing: Used in photography, creating new colors by adding RGB light.

Color Spaces

CIE Color Spaces

• CIE XYZ Diagram (1931): Maps how cone cells react to different wavelengths.
• CIE Lab and CIE Luv: More perceptually uniform color spaces considering human perception of lightness and color.
• CIE LCH: Easier to visualize colors (Lightness, Chroma, Hue).

Modern Display Technology

• Displays have evolved from CRT to OLED and QD OLED, improving color accuracy.
• Color depth in displays determines how many colors can be shown (e.g., 8-bit vs. 30-bit).
• Standard color spaces include sRGB, Adobe RGB, DCI-P3, Rec 2020, and Rec 2100 for HDR.

Color Perception and Psychology

• Color influences emotions and perceptions (e.g., blue for reliability, red for excitement).
• Designers use color theory to attract or manipulate audiences.

Creating Color Palettes

• Effective color palettes consider context, purpose, background, saturation, and contrast.
• Testing and adjusting colors using online tools can help find the best combinations.

Conclusion

• Understanding color and its perception significantly impacts design, art, and technology.
• The journey of color theory from pigments to modern displays illustrates the complexity and beauty of color in our lives.