This page explains in detail the interactions between the Terraria series and the Zelda series.
Terraria Patch 1.0.4[]
June 10, 2011
Terraria
Zelda
Among the new items introduced in the game through this patch is the "Hero's Clothes" a set of three vinity items called "Hero's Hat", "Hero's Shirt" and "Hero's Pants". These are clearly based on Link's trademark green tunic from the Zelda series, and the name might be a reference to The Wind Waker, where "Hero's Clothes" is the name that identifies the tunic. The Hero's Hat in Terraria also includes part of Link's blonde hair.
Notably the Hero's Clothes are recolored purple in the console versions of the game, resembling the forth Link from the Four Sword series.
Terraria Patch 1.0.5[]
June 23, 2011
Terraria
Zelda
This patch adds the Night's Edge, a very powerful sword crafted from other four swords: Blade of Grass, Fiery Greatsword, Muramasa, and Light's Bane (or else Blood Butcherer).
The way the Night's Edge is crafted might be a reference to the Zelda Four Sword series, considering that the swords are respectively green, red, blue and purple, the same colors as the four Links from the Four Sword games.
License[]
The creators of Terraria held no right over Nintendo's Zelda, but they only included minor references to the series. It's possible that the Hero's Clothes were recolored purple in the console version of the game to avoid legal issues.