Color display for dichromats

摘要

We have proposed colormaps to replace a widely used 216 colors palette in order to allow a designer with normal colour vision to simulate the colours seen by dichromats. As dichromats lack one class of cone photopigment, they confuse colours that differ only in the excitation of the missing class of photopigment. The method is based on the LMS colorimetric system, which specifies colours in terms of the relative excitations of the cones. We have constructed a rule to reduce any set of confused colors to a single three-component color specification. We have introduced a modification, assuming that the video display primaries and nominal white are representative of recent standards for Cathode Ray Tube (CRT) monitors and that its video-transfer function is a power function with an exponent of 2.2 ("gamma"). For everyday practice, replacing a normal palette by a reduced palette provides an immediate and efficient warning of possible losses of readability of a display by colour-deficients.