How diamond colors are graded

[chriscolumbus]

Commercially, colored diamonds are classified by using alphabet system. You can identify the range of diamond colorless to white can be as a letter ranging from 'D' through 'I'.
a)  Through 'L' is nearly colorless diamond.
b)  Faint yellow diamond will be a 'M.'
c)  A light yellow diamond can be classified as one of the letters 'N' through 'R' and
d)  Yellow diamonds in a range from 'S' to 'Z'.

The other shades are classified as colored diamonds, for example a very blue is known as ‘fancy colored blue diamond.' & a blue diamond is call a 'colored blue diamond'