Although most people believe diamonds to be clear or colorless, the majority of diamonds are yellow, brown, and black. Most of those diamonds find their way into industrial purposes, (drill bits, saw blades, etc.) The rarest of all diamond colors are white (or colorless).

As prices of diamonds rise, the shift to diamonds with some body color increases. It is very common to find slightly brown (called "Top Light Browns") or yellow diamonds in today's jewelry. The whiter the diamond is, the more valuable the stone is.

Diamonds are graded for color face down, against a white backgroud. Graders are looking at the actual body tone (hue) of the stone and comparing it to a set of master stones graded by the Gemological Institute of America. The diamond is then assigned a letter grade as seen on the accompanying chart. Most diamonds used for jewelry purposes fall into the Near Colorless Category - G to J

The Gemological Institute of America (G.I.A.) grades color alphabetically from D (totally colorless) to Z (yellow).For a diamond to be considered "colorless," the G.I.A. requires that it be a D, E, or F.  However, the D-Z scale is continuous, so the difference between an F and G is very small.  The average color for engagement diamonds in the United States is G to H. 

Jewelers have two tools at their disposal to judge the color of a given diamond.  The first is what's known as a "reference set" of stones.   A jeweler will compare the stone in question with a set master stones of known color, and make a qualitative determination as to the color grading of the stone in question.

When judging the color of a diamond, it is crucial to see the diamond unmounted.  Ask the jeweler for a master set of stones to make the comparisons yourself.  To do this, place the diamond in question next to the reference stones face down on a white piece of paper, and compare the color of the stones until you get the best match.

Perhaps the most important factor to consider when selecting color is the type of setting you plan on using.  If you plan on mounting the stone on a platinum or white gold setting, consider a diamond in the D-G range.  Yellow gold will be much more forgiving to a less than colorless stone, but regardless of the setting, the diamond will start to appear yellow if the color grade is lower than about J.