What size stones does GIA/AGS use as their master set for grading color?

[Dancing Fire]

 

[SimoneDi]

Different sets depending on the size of stone they are grading (I think).

 

[Karl_K]

See if this will tell ya....
https://www.gia.edu/doc/Coloring-Grading-D-to-Z-Diamonds-at-the-GIA-Laboratory.pdf

 

[AV_]

I must have hinted somewhere that this is no longer a reasonable way to measure color. Then, I do love the SPQR part of the world (and the foggy & the grainy & the slate-like, etc) - so I'd never know what to measure, only how.

 

[elizabethess]

See if this will tell ya....
https://www.gia.edu/doc/Coloring-Grading-D-to-Z-Diamonds-at-the-GIA-Laboratory.pdf

Thanks! For anyone reading the PDF check p. 308, Box B, 3rd Paragraph