Avoiding on‐screen metamerism in N‐primary displays

— The present paper describes a method for using more than three primaries in an additive-primary display. The method ensures that each tristimulus specification can be produced in no more than one way, even if a non-singular filter (i.e., one that does not reduce the dimensionality of color-matching space) is interposed between the screen and the viewer. Starting with N primaries, the method uses only three at a time, but these may be composites — fixed linear combinations of the original N. As further insurance against on-screen metamerism, a criterion on the primary spectra, based on the Binet-Cauchy theorem, ensures that a triad of primaries keeps its right/left-handed chromaticity ordering when a filter is interposed.