Shades of Grey

A large blue and red cube frame that has purple and green information banners hanging between top and bottom bars of the cube. There are also square orange and white shapes hanging from the frame.

How it works

Slide two panels across each other and observe how the grey squares seem to change in brightness or shade.

Things to try or ask around the exhibit

Can these grey squares turn darker or brighter before your eyes?


As you grow up, your brain learns to factor in shadows and bright light when you look at a scene. Your brain compares something to its surroundings (its context) to guess its shade. So, a patch of colour can appear brighter against a dark background, but suddenly turn darker when it’s placed in light and bright surroundings—simply because your brain is doing brightness gymnastics.

Finding the science in your world

The human brain judges the colour and shape of things based on how they contrast to their surroundings. This can be very difficult during foggy conditions, or at night time.