Coloured shadows An analysis of the phenomenon using photographic tools
lecture at AIC (International Colour Association) 2011

Short abstract

Studies on colour theory relegate the illusion of ‘coloured shadows’ to the footnotes. Rather than discussing the subject as an independent study, it is usually mentioned as a phenomenon of simultaneous colour contrast. Be that as it may, the coloured shadow is a highly intriguing phenomenon for a number of reasons.
In my presentation I am going to make an attempt to explain the illusion of the colour shadow, using photographic evidence collected during an experimental/artistic exploration of the phenomenon. I will demonstrate the parallels between the white-balance function of digital cameras and some technical terms used in cognitive sciences. Some of these include the principle of pre-learning, adaptive processes and anticipation (limiting variables in the environment to an acceptable level) and colour consistency.
In my presentation I will arrive at the conclusion that the term ‘colour shadow’ is a misnomer: the illusion is not that we see the grey shadow in colour, but the fact that we perceive the colour background as white. Using diagrams and photographic documentation, I plan to demonstrate that, analogous to the operation of the camera's colour-correction device, the mind perceives the phenomenon by ignoring colour light.