How long did it take to chisel out the stone for the prints Sorry could not resist.
I get no respect.

I think most corporations and companies that have specific colors still specify color in Pantone and the CMYK equivalent. However CMYK can only match a percentages of all the Pantone spot colors, I think it is something like half can be matched exactly, and about 25% come close and the remaining 25% are not very close at all.

Back in the days when we pulled our stone prints, I wrote a book Looking Good in Color in which I tried to explain all of this.