[bearmode]

I used to work as a GD professionally, Pantones/spot colours are incredibly important in the industry. Process printing (usually CMYK) is great, but often just not accurate enough, and I really doubt Coca Cola or whoever else would be too pleased with you swapping out their pantone colour for an alternative.

[sizzzzlerz]

Just think of the companies whose brand is represent by color. Coca Cola is certainly one but there's John Deere green, UPS brown, Caterpillar yellow, T-mobile pink, and Home Depot orange. I'm sure there are many international firms as well. Color is just as important to these companies as is their logo and they want to be damn sure it is represented accurately everywhere.