Color seems to be very straightforward, but it deals with more than most people think. Many people assume that most diamonds are "colorless" when in reality colorless diamonds are rare.
Most diamonds used in jewelry have some yellow or brown tint (mostly with a light yellow). However, natural diamonds come in an astounding variety of colors besides yellow and brown in the world, with the rarest being red, purple, and green. Pink diamonds are some of my absolute favorites to see!
GIA Color Grading Scale
The scale used for grading light yellow, brown, or gray diamonds begins with D (colorless) and continues through the alphabet to Z and is based on a diamond's lack of color. The closer the diamond is to grading as a D, the rarer the diamond. GIA has a completely different scale to grade other colored diamonds.
There are five color grade levels a stone’s color grade can fall into:
Colorless- D, E, F
Near Colorless- G, H, I, J
Faint- K, L, M
Very Light- N, O, P, Q, R
Light- S, T, U, V, W, X, Y, Z
Some of the color distinctions between the different grades are so subtle to the untrained eye that you might not notice the diamond's color immediately. These slight differences can make a big difference in the quality and value of a diamond.
A diamond's facets are similar to a bunch of mini mirrors reflecting the surrounding colors & light. When you look at your diamond, you're seeing the reflection of the colors around it as well. That is why in different lightings--sunlight, candlelight, indoor lights--your diamond might appear differently. Also it is good to keep this in mind when choosing your diamond's color and setting options. Diamonds will pick up tones of whatever metal color mounting they are in. You will sometimes see diamonds set with white gold prongs in yellow gold mountings to help bring out the brilliance.
Because we all see color differently, the color preference is totally personal to you. There are no wrong choices!