Why do colored paints and colored lights mix differently?

Colored lights add light together. Pigments absorb and reflect parts of the light that reaches them. Try both, then investigate why the amounts of each color matter too.

1Two ways to make a color

A color can be given off, or taken away

There are two completely different ways color can happen. Watch each one move:

Light gives off color

A glowing light adds color into the dark. Start with black, shine a color, and now there's color where there was none.

Paint takes color away

A paint is a filter that swallows colors. White light hits it, the paint eats some colors and bounces back only the leftover — that leftover is the color you see.

2So there are two games

Adding glow vs taking away

The adding game

Lights pile glow ON

+ + =

Each light adds its glow on top of the others.

starts dark → gets brighter ↑
The taking game

Paints swallow color

+ + =

Each paint swallows more, leaving less behind.

starts bright → gets darker ↓

3Your turn — stack them yourself

Pick a world, then pile on red, green, and blue

Choose which game you're playing. Then tap to stack each color and watch the spot change. (The light world also has a brightness dial.)

Nothing stacked yet tap a color to add it
Light brightness: full
DARK ROOMBLAZING

4The big race

A new recipe: what if one light is dimmer?

The practice used balanced red, green, and blue lights. Now compare two light recipes. Keep red and green full in both, but give the second recipe only half as much blue.

Guess before you watch

Red 1 + green 1 + blue ½: will this second light recipe still make neutral white, or will it have a yellow tint?

💡 Balanced lights · 1 + 1 + 1

…

💡 Less blue · 1 + 1 + ½

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