"Color" in a diamond refers to the relative body color of the gem material which is graded on a scale. The scale is based on the alphabet; it starts with the letter D and graduates all the way to the letter Z. The scale is broken up into 5 categories depicted in the slider graphic below. The saturation of tint increases as we move further down the color scale. The color a diamond most often graduates to is yellow, followed by brown, then gray. These tone differences can impact value. The yellow tone is caused by the presence of nitrogen in the earth at the time the carbon is crystallizing. The lack of nitrogen in the earth causes the diamond to be more colorless. The more nitrogen is present in the diamond the more yellow it will be. The brown tone is caused by the presence of nickel and the gray tone is caused by the presence of hydrogen.
If you're looking for "white" diamond you'll want to look within the D-J color range. If you don't mind a faint tint you can consider K-M. After the M color the tint becomes more obvious. Refer to our videos on diamond color below.