Colour, its measurement, discrimination and specification

The principles of colour specification and measurement are analysed and considered from the point of view of colour tolerances. Colour tolerances are considered under three main headings: (α) liminal, on basis of R.U.C.S., (β) technical, in terms of phenomena possibly involved, and (γ) economic. Tolerances for subtractive colour mixtures are analysed for practical application. A uniform-chromaticity scale of saturation is proposed.