Blending Colours

Mixing light with weighted averages

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Screens add red, green and blue light, each 0–255.
• Blending: α·F + (1 − α)·B, channel by channel.
• The eye is most sensitive to green, so grey conversion weights it most.

Steps

1. Match the sky
2. Blending is averaging
3. Glass over a background
4. Grey from white and black
5. Colour to grey
6. Light versus paint
7. Two layers of glass