Change colour swatch value in CC Library

What would your advice be re the CMYK - keep an eye on your guide?

Providing RGB/HEX, CMYK values for client brands is a difficult problem—I assume that’s what you are trying to do? In any case you want to make sure your client understands it is not possible to provide a single set of CMYK and RGB values that would reliably match a specified color, because the appearance of CMYK and RGB depends on the display or output device.

I think the best you can do is identify the brand color with a device independent color space like Lab, and then specify the RGB and CMYK spaces in your guide—there is no universal RGB and CMYK. Pantone’s Solid Inks (and other solid ink systems) are defined with measured Lab values, so you can use the printed solid ink swatch books to select the brand "source" color and identify the expected print and display destination CMYK or RGB color spaces, which is what I’ve done with my scripted guide.

Out of Gamut really just mean unreliable and not precise?

A good number of the Pantone solid inks are outside of a typical CMYK gamut, and some are outside of the sRGB gamut, which relative to other RGB spaces is small, but is the default RGB space for the major web browsers. My guide identifies the colors that are not in the GRACol Coated gamut—but many are on the edge, so depending on the color it might mean unreliable. Your 0|180|81 is well outside of the CMYK gamut—Photoshop shows out-of-gamut to the Working CMYK space with a warning triangle, which if you click it, shows the expected appearance change: