What is the Diamond Color Scale? How Color Affects a Diamonds GIA Grade

Diamonds come in all shapes, sizes, and colors that are graded on the diamond color scale. So, what is the diamond color scale and how does it affect the value of a diamond? Other than rare valuable colored diamonds, like pinks and blue diamonds, the color scale helps you assess how close a diamond's color is to be clear. 

Learn everything you need to know about the color scale for diamonds and how diamond color is graded. Find out why GIA’s diamond color scale is the standard metric across the industry. And, discover what it is about brown and yellow diamonds that warrant a lower color grade and why it decreases their value at your local jewelry store.

Understanding the Diamond Color Scale – GIA’s Color Grading System

The diamond color scale is a standardized grading metric for classifying the color quality of any particular diamond. In general, diamonds are more valuable the less color they have. There are rare exceptions to this, such as is true with ultra-valuable pink and blue diamonds, but these colors are not accounted for in the diamond grading system set forth by the Gemological Institute of America (GIA). 

The GIA diamond color grading system assesses the colorlessness of a diamond – or lack thereof. The appearance of yellow or brown coloration in a diamond lowers its color grade and decreases its value in the jewelry store display case. To assess the color grade of a diamond, a professional compare the diamond to a stone of known-color under controlled and standardized lighting conditions.    

How to Read the GIA Scale for Diamond Color

The color scale by GIA begins with the highest color grade of D and continues alphabetically until reaching the lowest color grade of Z. The only reason that the GIA diamond color grading system starts with D, instead of A, is because a competing system already used an alphabetic scale at the time of the GIA systems induction. So, to differentiate the new system from that which had previously existed, the GIA decided that the new scale starts with D and goes to Z. 

What Does it Mean if a Diamond is Graded at Z?

It is easy for the untrained observer to distinguish a D color diamond from a Z color diamond. It is almost impossible, however, for the untrained eye to distinguish a diamond grade Y from a Z. A diamond color with the grade of Z on the GIA scale has a pronounced yellow or slightly brownish hue, which some mistake for a “fancy diamond”

Like the rare pink and blue diamonds, which are not represented on the GIA color scale, it does not represent diamonds with stronger yellow or brown coloration. Z grade diamonds have a light yellow or slightly brown hue but are still transparent. Dark brown and deeply yellow diamonds exhibit a more pronounced coloration than exists on the GIA scale and are much higher in value than an ordinary diamond. 

Color Scale Suggestions for Diamond Buyers

It is almost impossible to tell the difference between color grades that are close to each other on the diamond color scale. But, it becomes more and more apparent if the diamond has a lower color grade, or if it contains any blemishes, the larger the carat of the diamond. If you are looking at a diamond that is over a carat, the best value is often in a diamond within the G-H color scale. 

If your diamond is under a carat you can expand your search to color grades between I and J. The smaller the diamond, the less noticeable small color variations. Also, be aware that the ring metal, in which the diamond is set, will reflect some of the colors through the diamond. So, yellow gold will amplify an already yellow diamond. 

In such a case, the shape and cut of your diamond determine how much of the underlying color shows through the stone. Round princess and other modified brilliant diamond cuts are the best options for keeping the color of the metal band from diluting the clarity of your diamond. Talk to a diamond specialist today for a free design consultation and to see a custom selection from the diamond color scale available in your budget.