Selecting your diamonds color. Diamonds come in every color of the rainbow. I am going to explain the color scale for a white diamonds, which is D thru Z. The whitest diamond would be the color scale letter D meaning pure white. The lower the letters go the more yellow tint you get in the white diamond. One way to save some money would be to go with a lower letter in the color scale but make sure the diamond has a strong blue fluorescence, which will make the diamonds appear whiter.