I consider the problem of numerically computing tristimulus values for a given spectral power density. In
particular, I examine the use of interpolatory quadrature rules for the solution of this problem. A good deal of
effort has gone into creating tables of weights and abcissas for solving this problem . Wallis  has proposed a
more sophisticated approach using Gauss quadrature rules. I show that the performance of these techniques can be
improved in a well-defined sense, and derive a method based on a new class of quadrature rules. These rules give
optimal performance in the sense that they maximize the overall degree of precision while simultaneously minimizing
the number of function evaluations.