The lack of natural body color is a major factor in determining
the value of a diamond. The most expensive are colorless
and are graded downward by the amount of yellowish or brownish
tint they have.
The best colour for a diamond is no colour at all. These
are known as "white diamonds". Other rare diamonds
with a pure colour, such as pinks, blues or greens, are
also valuable and are known as "fancy diamonds".
Because of other factors that contribute to the beauty of
a diamond, there are many beautiful stones below an M color
such as a very light yellow called "champagne"
and a darker yellow/brown called "cognac".
Colour grading scales from colourless to light yellow.
The differences from one grade to another are very subtle,
evidenced by the number of grades within each category shown
on the International Colour Grading Systems Chart (see diagram
below).
The diamond color grades are as follows:
D, E, F
Colorless. Loose diamonds appear colorless.
G, H, I, J
Near Colorless. When mounted in a setting may appear
colorless to the untrained eye.
K, L, M
Faint Yellowish Tint. Smaller diamonds look colorless
when mounted. Diamonds of 1/2 carat or more show traces
of color.
N - R
Very Light Yellowish Tint
S - Z
Tinted Light Yellow. These diamonds show increasingly
yellow or brownish tints and appear very "off-white".
