Charmonix is basically a matte version of box calf , natural charmonix is a color in this case the color of a finished leather,
so it is not an unfinished leather which would be capable of darkening with time...like vache naturelle which is an unfinsihed leather.
I hope it hasn't made things more confusing.
So Vache naturelle is an unfinished leather and it can darken with time and conditioning. gets water spots /stains if untreated. The Hermes paris stamp will be blind (no color and no gold or silver leaf in the leathers)
Veau Charmonix is a finished leather (has a top coat of color) does not go deeper in tone with time and conditioning like an unfinished leather, when the word natural is added it describes the color, it gets water blisters rather than water spots/ stains. The Hermes Paris stamp will be brown in color (there is will no gold or silver leaf in the letters)
OK?
All the best,doc