That, in a nutshell, is what the Pantone Matching System is about. It’s a system of describing colors, so the color you ask for on your commercially printed page, is what you get. That makes it very popular with the print industry.
The Pantone Matching System was first created in 1963, and Pantone have jealously guarded their intellectual property rights ever since. They particularly dislike attempts to create conversion charts. Not that I blame them, color charts are a big part of their business.
Now the picture of the Elephant and the Mouse is from a site which did offer a PMS <->RGB lookup. Pantone told them to stop.
And they did.
(Much to his regret, Dale has neither printer’s ink or graphic designers flair, coursing though his veins. He is very grateful to have spent time working as the IT guy for a large printing company.)