Miyamoto originally wanted The Legend of Zelda's Triforce to be made of electronic chips, had deeper plans for past/future elements

Zelda: Breath of the Wild dabbled more in the idea of technology than most Zelda games in the series, and it turns out that actually ties into Shigeru Miyamoto's original plans for the franchise. Back with the original Legend of Zelda, Miyamoto imagined the Triforce as being made of electronic chips, and that the game would take place in both the past and future. That's why Link is the name of the hero, as he's the 'link' between both times. Obviously Miyamoto got his wish when it came to time travel in the series, but we haven't quite gotten to the electronic chips idea yet!

What about Link's design itself? That comes from Takashi Tezuka, producer at Nintendo. A lot of things, such as Link’s sword, shield, and color, were all decided upon due to the hardware limitations of the NES. The team wanted to make sure Link and his items stood out clearly to the player. This is why Link ended up having a green outfit, which made Link easily distinguishable from everything else on-screen.

Believe it or not, when the team was considering using green for Link, they took inspiration from classic characters like Peter Pan! This obviously ties in to Link's ears as well, as they are quite long like Peter's.