Colorless stones are expensive. The color difference only really shows when compared side by side with a different stone. More often than not, the color of stones at retail establishments is very inaccurate. Unless you are an expert, you MUST get a certified stone to make sure that you are getting what you think you are getting. Yellow Very Light Yellow Light Yellow Color quality is critical because a diamond's value increases dramatically the more colorless it is.
Color determination consists of comparison with master set of diamonds under daylight conditions.
A single increase in a diamond's color grade can boost the value by thousands of dollars in some cases. There are 100 points in one carat. The size of a diamond measured in millimeters can also assist in determining approximately the diamond's carat weight. It is also important to note that size alone is not enough to determine a diamond's value. A large diamond holds little value if it lacks brilliance, purity and good color grade .