Diamond Color Chart
Diamonds come in a variety of colors, some of them highly prized (pinks, blues, even yellow). However in a white diamond, the presence of a yellow tint will lower the price of a diamond. The less body color in a white diamond, the more true color it will reflect, and thus the greater its value.
Every Emery.Diamond has been assigned a color grade by the in a viewing environment specially designed to eliminate color from surrounding surfaces as well as the light source itself. This allows the color of the diamond to be accurately measured. Minor differences in diamond color detected in this environment are very difficult if not impossible to detect in a normal environment. The diamond industry has adopted the GIA diamond color scale; almost every diamond sold today is rated using the GIA color scale, whether it was actually certified by the GIA or not.
The GIA grades diamonds on a scale of D (colorless) through Z (light color). All D-Z diamonds are considered white, even though they contain varying degrees of color. True fancy colored diamonds (such as yellows, pinks, and blues) are graded on a separate color scale.
GIA Grade Color Scale
While there are differences in color between D, E, and F diamonds, they can be detected only by a gemologist in side by side comparisons, and rarely by the untrained eye.
D-F diamonds should only be set in white gold / platinum. Yellow gold reflects color, negating the diamond's colorless effect.
The photo below shows a master set used by gemologists to grade color in diamonds. Each diamond to be graded is compared to the master set to determine where it should fall on the diamond color scale. The colors you see below are slightly exaggerated, since viewing diamonds face down makes their body color more pronounced. The face down orientation makes the detection of body color easier because brightness and fire are minimized when the diamond is face down.
Color becomes much harder to detect once a stone is set in a ring and placed in an environment that contains color (as opposed to the all white background used in diamond color grading). For instance, an H color diamond may look as colorless as a D when set in a ring under normal lighting conditions, especially if the two are not compared side by side.
Another factor that affects a diamond's apparent color is the color of the mounting itself. Yellow gold makes slight amounts of yellow in a diamond less obvious, while white gold or platinum mountings make the color in yellow diamonds more apparent.
The vast majority of untrained observers (and many gemologists) cannot distinguish a color grade from the one just above or below unless the diamonds are compared side by side in a controlled environment.
Color becomes more important as carat weight increases, because color is easier to perceive in a larger diamond, just as a carafe of white wine shows more color than a single glass.