Colour Combination Effects in Experimental Rooms * Monica Billger Department of Building Design, Chalmers University of Technology, Sven Hultins Gata 6, S-412 96 Gothenburg, Sweden Received 15 September 1998; accepted 15 December 1998 Abstract: This article deals with the way colours in a room affect each other through contrast effects and reflections. The study presented is based on the visual observations of the colour appearance of three inherent colours in a se- quence of experimental situations. My point of departure was a yellow, blue, and red room. The room had distinctly different colour appearances of the same inherent colours when observed at different locations. The effects of both contrasts and reflections were evident. However, reflection effects seemed to dominate the situation. In a study of small experimental rooms, different combinations of the same three inherent colours were systematically tested. Compar- isons were made to examine the differences in colour ap- pearance between monochromatic rooms and multicoloured rooms with varying colour schemes. The illumination was kept stable. In the cases studied, it was obvious how the colours in the two-coloured rooms became more alike or “neutralized each other.” The contrast strengthening be- tween abutting areas on the same level had distinct signif- icance for colour appearance and perception of space. However, not in such a way that the perceived colour differences became larger in the two-coloured room than between each monochromatic rooms. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 230 –242, 1999 Key words: contrast effects; reflections; colour appearance; experimental rooms INTRODUCTION Aim The main objective for the present investigation is to study some aspects of how colours affect each other in a room, and in particular to study the significance of contrast effects and interactions between reflecting surfaces. These two factors with their contradictory impact on colour appearance can both operate in a room. Our research aims toward deeper understanding of colour appearance in space. Colour is an important factor in giving a room its gestalt (atmosphere, character, and form). A room represents a complex situation, where several factors coop- erate. The combination of areas; the shape, size, and illu- mination of the room; the properties of the material (gloss, texture, pigment, etc.); and the qualities of the colours (hue and nuance) are all important for how colour appears in a certain situation. The knowledge about the actual appear- ance of coloured materials in buildings planned is the kind of knowledge that architects, designers, and others working professionally are obliged to gain through experience. Ob- viously, individual experience is invaluable, but learning by trial and error is usually expensive and the risks are often great. The feasibility of working consciously with colours, and to reach an intended result, is limited by our knowledge about how the appearance of coloured materials vary with context, that is how a coloured surface is affected by its spatial situation. The problem in focus for this study was how colours in rooms affect each other through contrast effects, and from reflections from one surface upon the other. In my earlier studies, 1 it seemed as if reflections had a dominant effect over— or reduced— contrast effects. Coloured surfaces in angular or opposite position “contaminated” or blended with each other, obvious contrast strengthening was only seen when differently coloured areas abutted each other on a wall or a floor. Nevertheless, one can ask if an overall simultaneous contrast effect can occur when contrasting colours are combined in a room. It is here assumed that such * Results from the study presented in this article have been presented in part in AIC Colour 97, Proc Eighth Cong Inter Col Assoc, Colour Science Association of Japan, 1997, pp. 913–916. Correspondence to: M. Billger; e-mail: Billger@arch.chalmers.se Contract grant sponsor: Swedish Building Research Council Contract grant sponsor: Swedish Association of Painting Contractors Contract grant sponsor: Swedish Painters Union Contract grant sponsor: Helge Ax:son Johnson’s Foundation © 1999 John Wiley & Sons, Inc. 230 CCC 0361-2317/99/040230-13 COLOR research and application