In the context of anti-piracy / anti-camcorder in digital cinemas a major requirement is invisibility of inserted pattern for the legal viewer watching the main cinema screen. On the basis of a multispectral projection system developed to create color metamers, we faced the need to explore and understand better color vision variability.This paper first presents the application context and the problem to solve. Then the CIE-2006 model is introduced, complemented with a brief overview of genetic aspects of color vision, as these were the basis for the study. Variability of color vision is then evaluated, first on a set of Stiles and Burch observers and then on observers in our digital cinema context.Two experiments are then presented, incremental steps towards the system improvement. The two experiments reveal coherent disparities for the different observers, modeling these disparities as L- and M- cone fundamentals shifts. The improvement between the first and the second experiment is shown in terms of closeness to a standard observer.This gain is a clear result of integrating color perception knowledge in the system design. It is as well a definite step towards acceptance of the metamer images by a wide and varied population of cinema observers.