Diamond pendants color typically refers to the diamond color scale. According to the GIA, diamond color actually refers to a diamonds "lack of color". Diamond colors outside this range are called "fancy diamond pendants".
Diamond Color Scale:
Diamond colors are assessed on a diamond color scale. Ideally diamonds have less color. The scale ranges from D to Z, with D color being the most highly desired and Z the least desired.
D, E, F Color Diamond Pendants
Most desired diamond bracelets, referred to as "colorless". These are the most expensive diamond pendants.
G, H, I, J Color Diamond Pendants
The next best colors are referred to as "near colorless". These are intermediate quality and have some value, although not top value.
K, L, M Color Diamond Pendants
These colors are not highly desired and are referred to as "faint". These are poorer colored stones.
N, O, P, Q, R Color Diamond Pendants
These diamonds are low color quality and referred to as very "light". Pendants aren't typically made from these stones.
S, T, U, V, W, X, Y, Z Color Diamond Pendants
The lowest quality diamond color is "very light". These are not typically used in pendants.
Fancy Color Diamond Pendants
Fancy color diamond bracelets may be any other color such as black, yellow, or pink. Depending upon size, quality and rarity, these can be ultra expensive diamond pendants.