Colour coding of data dependant on human perception of colour

A method for colour coding of data comprises selecting points in a psychological colour space that represent a range of colours for a colour scale for colour coding of data. Each point selected in the psychological colour space is mapped to a corresponding point in a physical colour space to enable a colour represented by each selected point to be determined, and the determined colours are then arranged into a colour scale. Defining a colour scale with reference to a psychological colour space allows the colour scale to be linear or nonlinear with respect to human colour perception; this can be achieved by using a regularly or irregularly distributed selection of points in a linear or nonlinear psychological colour space. Once data values are assigned to the colours in the colour scale, data arrays can be colour coded according to the scale, and presented to an observer for interpretation. An independent claim is included for a colour scale comprising a plurality of colours wherein the colour values of adjacent colours in the scale are spaced according to the positions of the colours in a psychological colour space.