Color grading is important to determine the grade and value of polished Diamonds. There are few (6) grading standard, the most common used are developed from GIA, which use a series of letters of the alphabet, the range from the finest white D-R light yellow (S-Z).
The grading is done by comparison with master-stones. Each set contains seven stone each represent one color and it is graded under standardized artificial light.
     Correct color and clarity grading is important, changes in color and clarity increase or decrease the value and purchase price of the Diamond.
     The color grading changes with the size of the stone. Smaller stone appear to have less color than bigger size through less body volume which the light rays have to travel trough the Diamond. Therefore for smaller stone the grading for each category changes visible.
For the comparison set, only stone from the same or similar size (weight) should be used for comparison, in order to get accurate color grading. The stone to be graded should lie between the lower and higher grade in order to make accurate judgment.
The cutting of the comparison stones should be similar to the stone graded.
No fluorescent stone should be used for master stone due too the body color, which changes when, viewed under sunlight.
Terms used in the trade for certain parcels: TTLB = tinted light brown,
TTLC = tinted light cape (yellow)
Nuts = Black or gray stone, with (spot) inclusions