Diamond color grades are not that hard to understand. Most jewelry shoppers know the color of a diamond is identified by a letter of the alphabet, with "D" representing the top color. More accurately, “D” represents the total absence of color, and stones that exhibit a slightly more tinted color are graded E, F, G and on down the alphabet. But what exactly does that letter grade represent, and what's the difference between a "D" and an "E colored stone.
If you have ever been in a big box hardware store's paint department you have likely seen one of those large racks of paint color chips - you know, those little pieces of colored paper which show the various colors of paint available for purchase. If you look at the whitest of white paint chips, then select the next five or so progressively less white chips, that small selection of colors of similar colors could be defined as representing the color range of "D" color graded diamonds. The next five or so slightly darker tinted chips might be considered as representing an "E", the next five chips or so a "F", and so on.
The difference between two color grades of diamonds could be defined as the observed color difference between the top level color of one grade range, and the top level color of an adjacent color grade range. It is noteworthy that a particular letter color grade is not a specific point on the color wheel, but a small, narrowly defined range of very similar colors.
When you purchase a graded color diamond you really don't know if your "E" color is just short of being graded a "D" color, or if your selected stone just missed being graded a "F" color. This range of colors within a listed grade is one of several reasons why stones that are graded the same are not often priced the same. A top level "E and bottom level "E" colored diamond are not priced the priced the same at the wholesale level, and that price differential is reflected in their retail selling price.