Unfortunately the Tartan weaving industry has not caught up with new fangled things like Pantone numbers.

Those were originally designed for paint and printing ink.

I'm afraid that you will have to settle for in fabric dyes are descriptions like Dk Green and Blue.

And even then it is not the same from one weaver to another.

I have many samples in my shop of the same Tartan from thee different weaving companies and they are completely different. All were listed as the same version so we are not even talking about the Mod-Anc-Weth- version thing.