The Ostwald system creates a color space based on dominant wavelength, purity, and luminance, mapping the values of hue, saturation and brightness. Establishing the values for these parameters is done with a disc colorimeter which mixes on a disk amounts of the pure spectral color at the dominant wavelength with white, and black . Thus the point in the Ostwald color space is represented by values C,W, and B to represent the percentages of the circle. For example 35,15,50 represents 35% full color, 15% white, and 50% black.
The OSTWALD system is based upon an analysis of reflectance curves.