OpticalIllusions.com

Colour illusions

Colours that change with their neighbours, spread into empty space or appear after the picture has gone.

Munker-White IllusionColour illusionsMunker-White IllusionThe same pink looks like two colours on blue and yellow stripes.Afterimage FlagInteractiveColour illusionsAfterimage FlagStare at a cyan, black and yellow flag and a red, white and blue one appears.Watercolour IllusionColour illusionsWatercolour IllusionA thin orange edge tints a whole white region pale orange.

Colour depends on context

Colour is built by the brain from comparisons between neighbouring regions and between opposing colour channels. That is why the same paint looks different on two walls, why a thin edge can tint a whole area and why staring at one colour leaves a ghost of its opposite.