Skip to content

Additive vs. Subtractive Color Mixing

Run the Additive vs. Subtractive Color Mixing MicroSim Fullscreen

About This MicroSim

Two side-by-side panels. Left panel labeled "Additive (Light - LEDs)": three overlapping circles in red, green, and blue on a black background.

Learning objective: Understanding - explain why light mixing and paint mixing produce different results.

How to Use

Use the on-screen controls - buttons, sliders, dropdowns, and clickable regions - to explore the idea. Every change updates the canvas immediately, so you can predict an outcome and then check it.

Iframe Embed Code

You can place this MicroSim on any web page by adding the following HTML:

<iframe src="https://dmccreary.github.io/moving-rainbow/sims/additive-subtractive-mixing/main.html"
        height="362px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

Grades 6-12

Duration

10-15 minutes

Learning Objective

Understanding - explain why light mixing and paint mixing produce different results.

Activities

  1. Explore (5 min): Open the MicroSim and try every control. Notice what changes on screen.
  2. Predict (5 min): Before each change, predict what will happen, then test your prediction.
  3. Discuss (5 min): Explain the idea in your own words and connect it to the LED code in Chapter 7.

Assessment

Ask students to describe, in one or two sentences, the relationship the MicroSim demonstrates and how it shows up when programming the LED strip.

References

  1. Chapter 7: Color Theory — The RGB Color Model and Color Mixing - the chapter where this MicroSim is used.
  2. Moving Rainbow Intelligent Textbook - the full course this MicroSim belongs to.
  3. MicroSims Reference - the standards behind these interactive simulations.

Original Specification

Full specification used to generate this MicroSim 
Type: interactive-infographic
**sim-id:** additive-subtractive-mixing
**Library:** p5.js
**Status:** Specified

Two side-by-side panels. Left panel labeled "Additive (Light — LEDs)": three overlapping circles in red, green, and blue on a black background. Where red and green overlap: yellow. Where green and blue overlap: cyan. Where red and blue overlap: magenta. Where all three overlap: white. Right panel labeled "Subtractive (Paint — Pigments)": three overlapping circles in red (magenta-red), blue (cyan-blue), and yellow on a white background. Where they overlap, colors darken toward brown/gray/black. Hovering over any overlap region shows a tooltip: "Red + Green light = Yellow" or "Red + Blue paint = Purple-brown". A toggle button switches between "Light Mode" and "Paint Mode" to emphasize the difference. Canvas: 700 × 350 px. Responds to window resize.

Learning objective: Understanding — explain why light mixing and paint mixing produce different results.