Actually, This article is impossible. A LAB* colorspace would suggest that color is not uniform at all, and we have large perceptual issues with it. Metamerism and all. There is both infinite Chromaticity and Infinite Luminance from a variety of directions to a point. You get an infinite amount of colors...

So what???? Just because We've decided to use the Pantone system to simply things doesn't mean a Pantone Swatch looks the same in all lights (Luminance). Within each swatch, there are infinite subcolors.

So yeah, it's impossible to copyright a magenta- although you can probably specify which Pantone magenta for the sake of certain pigment specifications you mean, you can't trademark magenta. There are infinite magentas...

An sRGB or Adobe RGB colorspace is just a specific cut of LAB*, since there is a specified singular white-point rather than a fluctuating relative luminance. You'll still get infinite color problems with both, as well as Metamerism (different colors via spectrum that look the same to the human eye)

So Trademark all you want. I'll stick your magenta on a yellow background. It's now a different magenta because of perceptual issues.