Carat | Cut | Clarity | Color
The absence of color gives a diamond its great value. If any color is detected, even slight, the diamonds value is depreciated. Some of the "fancy" diamonds can be valued for their color. For example a yellow diamond.
There are 2 categories of diamonds in respect to color:
1. White Diamonds - These are diamonds falling within GIA's D to Z color grading scale, traditionally used for engagement rings and fine jewelry.
2. Fancy Natural Colored Diamonds - These are diamonds with faint to vivid saturations of hues such as blue, yellow, or pink, frequently used for fashion jewelry.
White Diamonds graded D through F are naturally the most valuable and desirable because of their rarity. If there is a budget in place diamonds graded G through I, do not have any color that can be detected by the untrained eye. Diamonds graded J through M, have color that can often be minimized or almost completely hidden by carefully selecting the right setting or mounting style and color. For example, yellow metals will hide traces of color in a colorless diamond, while white metals will enhance it.
With fancy color diamonds, however, there is a large difference. The discussion turns to the purity and richness of the diamond's color.
Yellow is the most commonly-occurring fancy color. Red and green diamonds are extremely rare to find. The price of fancy colored diamonds is dependent on several factors: the particular hue, or spectral color, of the diamond (the rarer the color, the greater the cost); the richness or saturation of the color (ranging from very light to light to intense to vivid); and the purity of the color (i.e. whether the color is bright and clear, or 'muddied' by the presence of other color-causing trace elements). There are laboratory created diamonds. They are either heat / radiation treated or chemically created. They are of lesser value than authentic fancy diamonds.