Add Sherwin Williams' color set

[oxinabox]

This is 7750 names colors given as RGB, in a pdf.
https://images.sherwin-williams.com/content_images/sw-pdf-sherwin-williams-color.pdf

Need to check the copyright on the list.

[kellertuer]

Nice list, what would we do with naming collisions to existing colours here?

[oxinabox]

Same thing we do elsewhere, which is over-write them with the one from the smaller set.

Possibly we also should provide an API for getting a name from a particular set.
Or automatically also generated qualified names like sherwin-williams.brightred

[kellertuer]

I like the qualified names, since this would also solve the other problem over at paul-tol.vibrantblue sounds like a very good solution that can be automated.