No three-color display can faithfully reproduce all color percepts. Suppose you wanted to design a three-primary display with the largest possible gamut (measured in terms of area on the chromaticity diagram).
(a) Argue why all three primaries should be on the boundary of the horseshoe.
(b) Find the xy-coordinates of the horseshoe boundary and then search for the optimal location for the three primaries.
(c) Approximately what percentage of the area can you cover with three primaries? With four? With five?