All ages

Colouring with Light

Colour a scene by turning red, green, and blue pixels on and off.

How to Use It

Choose a scene, then use the on-screen tools to add or subtract light directly to the ‘canvas’.

What Science Tells Us

Human eyes typically have three types of colour receptor: ones most sensitive to long wavelengths (red light); ones most sensitive to medium wavelengths (green light); and ones most sensitive to short wavelengths (blue light).

Additive colour mixing simply adds a little of each colour—red, green or blue—to stimulate each receptor type in just the right way to create a certain mix.

Things to Try or Ask

What happens when you create a triangle pattern by adding a spot of each colour at the corners that overlap in the centre?

If you create a white area by adding red, green, and blue, what happens when you create a triangle pattern by removing a spot of each colour at the corners, overlapping in the centre?
 

Finding the Science in Your World

All colour screens that emit light mix colour additively: they start with black, then add measured amounts of red, green and blue light to achieve a desired mix.