[chrisseaton]

> Your last sentence is just wrong.

How do you express metallic gold 817 using RGB.

Which of those components gives you how metallic it is? It's not even 1-1 as it depends on the paper used! Their own books show how lossy it is - they show the corresponding CMYK and it often barely matches.

> within-gamut

Ah so you already knew it wasn't true.

[pxx]

The cardinality of one set is much bigger than the cardinality of the other one. Pantone 871 is mapped to #84754e. If you see #84754e and also get the instruction "use only Pantone colors", it is not ambiguous!

[chrisseaton]

Someone needs a lookup table to map those back - that’s what you’re paying for. They aren’t claiming to ‘own’ the colours.