A diamond can divide light into a spectrum of colors and reflects light as color flashes called fire. The less color in a diamond, the more it affects the brilliance of the diamond.
The diamond color grading scale varies from totally colorless to light yellow. The differences between one diamond color grade and another are very subtle and difficult to distinguish by the untrained eye.
D : Absolutely Colorless: The highest color grade - extremely rare.
E :Colorless: Only tiny traces of color can be detected by an expert gemologist - rare diamond.
F : Colorless: Slight color detected by an expert gemologist; still considered "colorless" grade. Perfect or almost perfect color - a high quality diamond.
G-J :Near colorless: good to very good color, and this diamond may "face up" colorless when mounted, especially in white gold or platinum.
K-M : Light but noticeable yellow or brown tint. Not recommended for larger diamond stone purchases, especially in engagement rings.
N-Z :Noticeable color.
Tint visible to the naked eye, even when mounted. Colors are increasingly more dramatic.
Out of the 4 C's, color and cut are the two most important characteristics of a diamond. Do not compromise on color. An "H" color or better is usually best.