Starting with an analysis of the dimensions of the colour gestalt the paper describes two principly different perceptual colour systems - the colourcharacterizing NCS-system and the discriminative system. The relationship NCS/physical stimulus is described in a bit unusual way also taking in account luminous colours. A brief critical summary of Munsell, DIN and Ostwald shows that they must be mixtures of different concepts. Finally are sketched some new research projects around colour in environment - variation in colour and colourdifferences depen-ding on varying outer conditions the colour-gestalt and its dependence of distinctness of boarder line - a theory for colour-combinations- other psychological relationships