When you want that "I'm with the band" look, you make like a rock star and smudge your eyeliner. If you want that same IDGAF vibe with your hair color, there's a similar technique colorists employ: ...
Bird diagram from the 1886 'A nomenclature of colors for naturalists : and compendium of useful knowledge for ornithologists' by Robert Ridgway (via Smithsonian Libraries) Colors in the 1912 'Color ...