The concept of the gamut of a colour reproduction system is explained,
starting from the spectrophotometric description of colorants used. T
he extension is made from spectrophotometry to CIE 1931 XYZ colorimetr
y, a system still in use for the description of colour gamuts. Advanta
ges of the CIE 1976 u',v' uniform chromaticity chart are discussed and
related to CIE 1976 Lu+v* and L*a*b* uniform colour spaces. The use
of Status A trilinear density plots is described and examined in terms
of visual uniformity related to the Munsell system. The three-dimensi
onal representation of a colour gamut in CIE 1976 La*b* colour space
is related to colour sensitometric results which explain and allow int
erpretation of the colorimetry. Applications of the systems reviewed a
re made to real surface colours and a variety of reflection and transm
ission photographic systems under different conditions of use, as well
as to images formed by visual display units and broadcast television.