The Goron Tunic was the red outfit Link obtained near the Fire Temple in The Legend of Zelda: Ocarina of Time. It had only one real use, and that was to survive in the volcanic areas without losing hearts by the second. Wearing red clothes magically makes volcanoes feel like room temperature in the Zelda games.
So I hope you like wearing red, because you have to do one dungeon with it equipped. You can wear it in normal areas as well, but I always liked the blue tunic.