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LET'S EXPLORE Science

How are colours produced?

A prism splits light into the spectrum colours.A prism splits light into the spectrum colours.Sunlight—bright white light—is a mixture of all the colours of the rainbow. This is called the spectrum of light. The different colours can be seen when a beam is shone through a shaped piece of glass called a prism. The prism bends the light waves. Red waves bend the least, while violet waves bend the most. Raindrops sometimes act as mini-prisms. They split light into the colours of the spectrum. We see them as a rainbow.



Raindrops split sunlight, creating a rainbow.Raindrops split sunlight, creating a rainbow.

 

 

Grass and flowers reflect different colours of light.Grass and flowers reflect different colours of light.

Seeing colours

We see colours because some objects reflect different colours of light. Some reflect mostly one colour. Grass, for example, reflects mostly green light, so it appears green. Others reflect a mixture of colours. 







Primary colours

A close-up view of a computer screen, showing pixelsA close-up view of a computer screen, showing pixelsOnly three, red, green and blue are needed for our eyes to see every colour there is. These are called the primary colours of light. Many different colours can be made by mixing together primary colours in different amounts. For example, red and green together make the colour yellow. Mixing all three together makes white light.

Why is the sky blue? Sunlight is made up of different colours. Red light passes straight through the air, but blue light is scattered in all directions by the tiny molecules of air in the Earth's atmosphere. It is this blue light that we see when we look up at the sky.

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