Eliasson gives light and colour the same significance as more physically tangible materials. Optical phenomena are investigated and examined. In Room for one colour (1997), a room is filled with a yellow mono-frequency light in which the eye can only distinguish yellow and black. When the viewer leaves the yellow room, an after-image in the complementary colour (blue) remains on the retina. The phenomenon is fleeting and fades away after the initial exposure. The work exists not only inside the room but is assimilated by the viewer.

Movement in various forms characterises many of the exhibition’s installations. Sometimes movement is an inherent part of the work, as in Ventilator (1997), where a fan circulates in irregular ellipses above the visitors’ heads. In other works the components are static, and the viewer’s own movements take centre stage, as in Beauty (1993) where the perception of the work is entirely dependent on viewer’s position in the room. In some cases viewers move through the work, as in Seu corpo da obra (Your body of work) (2011). In this installation, monochromatic colour filters create semi-transparent walls that float in the room. A labyrinthine architecture of coloured space is created. Through the viewer’s movements in the room, the filter’s three colours – magenta, yellow, and cyan – can be seen overlapping in a variety of configurations as various hues emerge in the viewer’s vision.