This word may have been formed from French gris and now-obsolete grisellé, but simply saying “it means ‘grey'” doesn’t begin to cut it. You can see a gristly old sea salt, as grisly a sight as a buzzard or grizzly, his face frazzled and his muzzle drizzled with hoary stubble… Not someone you’d want to nuzzle, not a sizzler, but perhaps a bit of a puzzle.
Oh, we can see that buzz-saw zz cuts both ways: sometimes a dazzle and sometimes a fizzle – could be lightning, could be a short circuit, as it shifts from the alveolar buzz of the /z/ to the steady-state, almost guttural hum of the syllabic dark /l/ (not the light one, made with just the tongue tip in action, but that English syllable-ender with both back and tip of tongue raised, as though cupping and containing the sound in its central hollow). And likewise the growling gr, which greets with great or a grunt, can be grand or gross, bright green or dull grey… Join the gr and the zzle and the result, with all its echoes, is the grey not of shiny silver but of sooty snow.
Some people will write of a gray, grizzled something or say a thing is grizzled grey – evidently envisioning grizzling as an act with greyness as a possible result. (Could you have something grizzled pink? But even some noted literary magazines have printed an instance or two of this double coating.) But inasmuch as there is a verb grizzle, it’s backformed from this adjective, which has the ed suffix not of verbal past tense but of noun association and effect. And what is grizzled? Most often, beard, hair, face, head; the type of person is old, a man, perhaps a veteran.
What we have here, then, is a word that drags itself in from the awful weather, sits grimly at the counter, drinks a cup of burnt black coffee and, with a voice like wet rocks grinding, speaks of the battles of a life scraped from the bottom. The grey that got that way the hard way.