Mixing Coloured Light

Looking at a bright colour produces an after-image in the complimentary colour: red produces a blue-green after-image.

Colour Activities Table
Make your own colour spinners and find out what happens when you spin them.

Colour Code
Write a message using different coloured pens - use coloured gel filters to decode the overlapping messages.

Colour Filters - light table
Overlapping coloured filters produces colours by subtracting colours from white light. In this exhibit, you can see what part of the spectrum is being absorbed.

Colour Mixing - Adding Coloured Lights
Control the brightness of overlapping red, blue and green light beams to produce all the colours of the spectrum and more. Shows how three colours are enough for colour television and colour films.

Colour Mixing - Colour Television
Shows how a colour T.V. picture is made with only red, green and blue dots.

Colour Mixing - Taking colours away from white
Experiment with colour filters on a light box - this is the opposite to mixing lights (additive mixing).

Colour Printing - light table
Shows how yellow, magenta, cyan and black transparencies or inks can produce a full-colour scene.

Coloured Shadows
Produce different coloured shadows and explore colour mixing.

Colours from black and white (Benham's Disc)
This rotating black and white pattern stimulates the colour receptor cells in your eye to see colours.

Goethe's Coloured Shadows
Shows that our brain can alter the colour balance of a scene to compensate for changes in the colour tint of the lighting.

Land Slides
Make a full colour picture by projecting red, green and blue images of a scene together. If the red image is projected together with a black and white version of the green; instead of just pinks the picture is almost fully coloured. This puzzle, first demonstrated by Edwin Land, tells us a lot about how we really see colours.

Mixing your own coloured lights
Mix red, green and blue light on a screen to produce not only any of the colours in the spectrum, but white, black and the magentas.

Spectrum from a Grating
A spectrum is produced using a diffraction grating. Coloured filters allow some colours to go through them.

The Stroop Effect (Confusing Colours)
It is difficult to read a list of colours when words and colours disagree.

White from a coloured disc (Maxwell's Disc)
When a three coloured disc spins round fast the 'colour' you see depends on the widths of the sectors - in this case it produces white.

White from a rainbow disc (Newton's Disc)
When a disc of rainbow-coloured sectors spins, the colours merge at the eye - with our choice of sectors to produce white.

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