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Color Theory

  • Additive Color Mixing – The process of mixing light wavelengths to create new colors. Uses red, green, and blue (RGB) as primary colors.

    • Red + Green = Yellow

    • Green + Blue = Cyan

    • Blue + Red = Magenta

    • All three together = White

  • Subtractive Color Mixing – The process of mixing pigments or filters, where certain wavelengths are absorbed, leaving only reflected colors. Uses cyan, magenta, and yellow (CMY) as primary colors.

    • Cyan + Magenta = Blue

    • Magenta + Yellow = Red

    • Yellow + Cyan = Green

    • All three together = Black (in theory, but often dark brown due to imperfect absorption)

  • Filters & Color Absorption

    • Red Filter – Absorbs green and blue, allowing red to pass through.

    • Green Filter – Absorbs red and blue, allowing green to pass through.

    • Blue Filter – Absorbs red and green, allowing blue to pass through.

    • Cyan Filter – Absorbs red, transmits green and blue.

    • Magenta Filter – Absorbs green, transmits red and blue.

    • Yellow Filter – Absorbs blue, transmits red and green.

  • Effects of Filters on Colored Light

    • A red filter over a white light source = Red light output

    • A cyan filter over a red light source = Black (since cyan absorbs red light)

    • A yellow filter over a blue light source = Black (since yellow absorbs blue light)

  • Practical Applications of Optical Mixing

    • Stage Lighting: Additive color mixing is used to create different lighting moods.

    • Photography: Filters are used to correct or enhance colors.

    • Printing: Subtractive mixing (CMYK) is used in color printing.

    • LCD Screens: Pixels use red, green, and blue light to create all displayed colors.