This paper explores the relevance of three concepts for shape defining colour design, developed from camouflage theory. The visual distinction between colour patterns as defining either colour or shape allows colour design to interfere with shape defining patterns given by any specific light situation. The concepts counter-/co-shading, disruption and constructive shading are applied in descriptions and analysis of colour design effects, on both a selection of painted geometrical reliefs and existing buildings. Analysing colour design as interacting with shape defining patterns allows an explanation of how colour design affect the visibility of shape and may produce a more complex visual situation. Inconsistencies result in ambivalent visibility of shape, affecting the impression of the light situation and atmosphere. In conclusion the three developed concepts clearly contribute to a more precise understanding of colour design effects on the visibility of shape in an architectural context.