Color Mixing Simulator: Additive & Subtractive

simulator beginner ~6 min
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#C86432 — warm orange

R:200 G:100 B:50 produces a warm orange in additive mixing. Switch to subtractive mode to see how the same values behave as pigments.

Formula

Additive: R_out = min(R1 + R2, 255) for each channel
Subtractive: R_out = R1 × R2 / 255 for each channel
Luminance = 0.2126R + 0.7152G + 0.0722B

Two Worlds of Color

There are two fundamentally different ways to create color: adding light or subtracting it. Screens emit RGB light — combining red, green, and blue in different proportions to create millions of colors. When all three shine at full intensity, we see white. Paints and inks work in reverse: each pigment absorbs certain wavelengths, so mixing more pigments removes more light. CMY pigments combined should theoretically produce black — total absorption.

The RGB Additive Model

In additive mixing, colors get brighter as you combine them. Red plus green makes yellow. Red plus blue makes magenta. Green plus blue makes cyan. All three make white. This is counterintuitive if you grew up mixing paints, where combining colors always gets darker. Every pixel on your screen is three tiny RGB sub-pixels, blending at a distance your eyes cannot resolve. Adjust the sliders to see how different RGB values combine into the full color spectrum.

The CMY Subtractive Model

Subtractive mixing starts with white light (or white paper reflecting all light) and removes wavelengths. Cyan pigment absorbs red, passing green and blue. Magenta absorbs green. Yellow absorbs blue. Mixing cyan and magenta absorbs both red and green, leaving blue. Mixing all three should absorb everything — but real-world pigments are imperfect, producing muddy brown instead of true black. That is why printers add a separate black (K) ink: CMYK.

Why This Matters

Understanding the difference between additive and subtractive mixing is essential for anyone working with color professionally. Designers must know why a color looks different on screen versus in print. Photographers must understand white balance and light mixing. Film and stage lighting technicians work entirely in additive space. And the math behind both systems — simple multiplication for subtractive, simple addition for additive — is the foundation of all digital color management.

FAQ

What is additive color mixing?

Additive mixing combines light. Red, green, and blue (RGB) are the primary colors. Mixing all three at full intensity produces white. This is how screens, projectors, and stage lighting work — adding more light creates brighter, lighter colors.

What is subtractive color mixing?

Subtractive mixing combines pigments or filters that absorb (subtract) wavelengths from white light. Cyan, magenta, and yellow (CMY) are the primaries. Mixing all three absorbs all visible light, producing black. This is how printers, paints, and dyes work.

Why are RGB and CMY complementary systems?

Each CMY color is the complement of an RGB primary: cyan absorbs red, magenta absorbs green, yellow absorbs blue. This duality means screens (additive) use RGB while printers (subtractive) use CMY(K). They are two sides of the same color coin.

Why do printers use CMYK instead of CMY?

In theory, mixing cyan, magenta, and yellow pigments should produce black. In practice, impure pigments create a muddy brown. Printers add a dedicated black (K for 'key') ink for crisp blacks, better text rendering, and cost savings — black ink is cheaper than mixing three colors.

Sources

Embed

<iframe src="https://homo-deus.com/lab/color-science/color-mixing/embed" width="100%" height="400" frameborder="0"></iframe>
View source on GitHub