COLOR While most diamonds appear to be white, virtually all have slight traces of color. Evaluating a diamond's color for grading purposes is done by measuring the degree to which a diamond approaches colorlessness. Gemologists and jewelers describe the color of diamonds on a letter scale beginning with D (colorless) and moving through the alphabet to Z. The degree of colorlessness is not easily visible to the naked eye. D, E, and F color grades are more expensive because they are more rare. However, well cut diamonds with good clarity of all color grades can be equally dazzling as it is the interplay of the 4C's which determines each individual stone's unique beauty.