Key learning points

1. Colour is detected in the eye by the R, G and B ‘cone cells’ that each detect a range of colours of light.
2. The colour of an object in white or coloured light depends on the amounts of R, G and B light it is reflecting.
3. White objects reflect all colours of light so look the same colour as the incident light (whether white or coloured).
4. The colours of light that an object does not reflect are absorbed. Black objects absorb all colours of light.
5. In red/green/blue light, an object will appear red/green/blue if it reflects that colour, and black if it does not.

Keywords

• Reflect - to hit a surface and ‘bounce’ off

• Incident - a word used to describe the incoming light that hits a surface

• Scatter - to reflect light in many directions at once

• Cone cell - the cells at the back of the eye that detect colour

• Absorb - a material that absorbs light / gains energy from light travelling through it, decreasing the amount of light

Common misconception