Handkerchief
From YPPedia
The Handkerchief is a trinket.
Colors
They have two colors per trinket, and thus 729 unique versions:
Navy/white handkerchiefs were readily available in the daily Cleaver's Blue Hanky automated swordfighting tournament. Purple/blue handkerchiefs are rewarded as a prize in the Drown Yer Sorrows Drinking tournament.