A diamond's color has a significant impact on its appearance. With its many prismatic facets, a colorless diamond reflects light into a spectrum of hues, a characteristic often referred to as "fire". The presence of noticeable color in a diamond may reduce its ability to reflect light. Consequently, diamonds with lower color grades will not show the same luminosity and fire as those with higher grades. The most valuable diamonds have little to no detectable color.
Diamond Color Grading
Colorless Diamonds (D, E, F): D is the highest color grade for a diamond. Stones belonging to this color grade are almost colorless and icy white. E and F color graded diamonds have very slight traces of color in them that remain undetected unless examined by a gemologist. This group of diamonds is rarest and the most expensive one. Such diamonds are best mounted on white gold or platinum. Yellow gold or other colored settings are generally avoided as they may take away from the luminous beauty of this category of diamonds.
Nearly Colourless (G, H, I, J):This color grade displays nearly no color. The diamonds in this category appear colorless to the naked eye. If you are looking for a diamond to mount in platinum or white gold, go for G or H color graded stones. For yellow gold mounts, you can opt for I or J graded diamonds. The diamonds of this group are less expensive than the D-F group and are often used as the central stones in rings.
Faint Colour (K, L, M): Diamonds in this color grade possess a slight tint of yellow that can be seen even with the naked eye. Due to this, diamonds of this group are not as desirable as the two previous groups. They are also not as rare or as expensive as the other two groups mentioned above. Diamonds belonging to this group can be set in yellow gold mounts for an appealing look.
Very Light Colour (N, O, P, Q, R): This group of diamonds has visible color. Often the color is a tint of yellow or brown. There is very little demand for such diamonds and they are available at a much low price range. Most reputed jewelers avoid dealing in this category of diamonds for making ornaments.
Light Colour (S-Z): The diamonds belonging to this color grade exhibit easily noticeable yellow or brown tint. As they are placed at the low end of the color grade, they are among the least expensive diamonds. Such diamonds are usually not considered for making ornaments.