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Color Mixing: Light vs Paint

·423 words·2 mins
Others color fun x2
Table of Contents
Colors - This article is part of a series.
Part 2: This Article
There are 2 light sources: Additive system and Subtractive system.

Color mixing works differently depending on whether you’re dealing with light (screens, LEDs) or pigments (paint, ink). They follow completely different rules.

Additive Color Mixing (Light)
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Additive means adding more light makes things brighter. Often used in:

  • Screens (phones, TVs, monitors)
  • Projectors
  • Stage lighting
  • Anything that emits light

Primary colors:

  • Red
  • Green
  • Blue

These are often called RGB colors.

👉 How it works

  • Red + Green = Yellow
  • Green + Blue = Cyan
  • Blue + Red = Magenta
  • Red + Green + Blue (full brightness) = White

Because the human eye has three types of color receptors (red, green, blue sensitive). Mixing light stimulates these receptors in different combinations.

For example: Your TV shows yellow by turning on red + green pixels at the same time. The screen never uses “yellow paint”—it’s just light mixing.

Subtractive Color Mixing (Pigment)
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Subtractive means adding more pigment makes things darker. Often used in:

  • Paint
  • Printer ink
  • Dyes
  • Anything that absorbs light instead of emitting it

Primary colors:

  • Cyan
  • Magenta
  • Yellow

Commonly called CMY (or CMYK for printing).

Each pigment absorbs (“subtracts”) certain wavelengths:

  • Cyan absorbs red
  • Magenta absorbs green
  • Yellow absorbs blue

Mix results:

  • Cyan + Magenta = Blue
  • Magenta + Yellow = Red
  • Yellow + Cyan = Green
  • Cyan + Magenta + Yellow (strong pigments) = Almost black

(Printers add black ink “K” for deeper blacks)

Pigments work by removing (absorbing) light. Whatever light is not absorbed gets reflected to your eyes.

Example: If you mix blue paint and yellow paint, you get green because both pigments absorb different parts of the spectrum—only green survives the trip to your eyes.

Quick Comparison
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FeatureAdditive (Light)Subtractive (Paint)
What you mixLightPigments
Primary colorsRed, Green, Blue (RGB)Cyan, Magenta, Yellow (CMY)
More mixing leads toBrighter → WhiteDarker → Black
Example outputsR+G = YellowY+C = Green
Where usedScreens, LEDsPaint, printing

Why Do They Oppose Each Other?
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Because:

  • Light mixing = combining wavelengths
  • Paint mixing = absorbing wavelengths

They operate in opposite directions. That’s why:

  • RGB primaries produce CMY secondaries
  • CMY primaries produce RGB secondaries

They are complementary systems.

Real-World Examples
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🌟 Why white light + prism gives rainbow?

White contains all wavelengths → prism spreads them.

🎨 Why mixing many paints gives brown/black?

Lots of pigments = lots of absorption → almost no light reflects back.

📱 Why digital colors look brighter than paint?

Light shines directly into your eyes → much more intensity.

Colors - This article is part of a series.
Part 2: This Article

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