Working in existing built contexts is an essential aspect of most architectsi activities. The development of a conceptual and technological basis for the digital support of design directly on site, with and within the existing building is the main focus of the research project “Spatial Augmented Reality for Architecture”. This article describes one part of the research project: the final evaluation of the technologies developed and the concepts applied for an architectural colour reconstruction scenario on site. This project is funded by the German Research Foundation (“DFGi).