Of course I do. Anybody can tell King's sword doesn't have haki on it while Zoro's do following the visual clue I just explained.
These are swords without armament on them; you can clearly distinguish that one half is clear and the other isn't:
And these are sword with armament, in which it goes from 50/50 to a clearly predominant black with a thin line of white in the middle:
I mean, it's as easy as comparing how distinctive Shusui looks regarding non imbued swords:
Or, again, noticing the change from the first half to the second half of Zoro's sword as he's in process of imbuing it:
It's not that hard, really.