What to do with this activity?

Isaac Newton (yes, the same guy who discovered gravity) proved that white light splits into a range of colours - the colours of a rainbow - when shone through a prism. That was way back in 1672, over 300 years ago. Newton also invented a colour wheel to show the relationships between the colours. If you spin Newton's wheel fast enough, the colours appear to merge again into white.    

Make a spinning Newton's wheel as a science experiment or as an arts and crafts project. Here's a IncredibleScience.com youtube video showing you two ways to make a spinning Newton's disc. Have fun watching these kids spin the discs/wheels and watch how the colours merge into white (or off white if the colours are not pure). Click on the above PDF link to find a Newton's disc that you can print or copy. 

You can make another kind of colour wheel with six sections, showing the primary and secondary colours (also on the PDF link above). The three primary colours are red, yellow and blue. All other colours are a mixture of these three colours. If you mix equal parts of two primary colours, you get the secondary colours - orange (a mixture of red and yellow); green (a mixture of yellow and blue); and purple (a mixture of blue and red). Notice how the colours on opposite sides of the circle are complementary - they make a dramatic contrast.