Colour shadow theatre is a large, star-shaped room which viewers can enter and participate in an enveloping color experiment. In work such as Colour shadow theatre, Eliasson inserts the user directly into the work, and into the role of subject and co-producer.

'In Colour shadow theatre, there are no objects, only bodies moving between the lights and projeted images. As more people congregate and move in the space, the projected images superimpose, merge, detach and proliferate, their colours intensifying or shadows deepening as they draw closer to one another, lightening as they pull away. No stable image is created; the visual phenomena are ephemeral. It is pure performance, pure event.'

(Eve Blau, 'The Third Project', in: Olafur Eliasson: Your Chance Encounter, 2010)