The Legend of Zelda: Breath of the Wild is one of the most acclaimed games of the modern era. As the highest rated Zelda title on Metacritic after Ocarina of Time, Breath of the Wild is an immense success. It changed the gameplay formula, giving players an expansive open-world Hyrule to explore. Another aspect separating itself from past Zelda titles was the clothing Link dons.
Instead of the usual green tunic and hat, Link's default look is blue. Game Director Eiji Aonuma explained in an art book (transcribed by Nintendo Everything) that abandoning Link's usual appearance was the result of wanting to make him a more "neutral" protagonist.
Eiji Aonuma: "We thought that the iconic green tunic and hat had become expected, so we wanted to mix things up and update his look. Interestingly, though, nobody on the team said, ‘Let’s make him blue!’ It just organically ended up that way."
Art Director Satoru Takizawa also stated that the team went through "close to one hundred designs" for Link. Senior Lead Artist Yoshiyuki Oyama explained that blue stood out against the game's backgrounds. It is interesting that Aonuma said he wanted to make Link look like someone who didn't appear as "an already accomplished hero." Aonuma said it "could get in the way of the players immersing themselves in the game." This logic is understandable. If Link was given his green tunic, the player would probably already feel like the Hero of Time. By giving Link something new and less iconic, the player can see Link as becoming more and more the hero with every boss defeated.
Link's blue look has been well received. In fact, his Breath of the Wild look is used as the default skin in Super Smash Bros. Ultimate. For the first time, the green tunic is regulated to alternate outfits. It's unlikely that the blue look will eclipse the classic design, but for right now, it makes sense that Nintendo would want to promote one of its most critically acclaimed games.
Interestingly, Zelda also sports a blue look in Breath of the Wild. However, this appearance was not chosen for Ultimate. Masahiro Sakurai explained at E3 that Breath of the Wild's Zelda is "more into research than fighting." Thus, her look from A Link Between Worlds was chosen. Back to Link, it's likely that Link's blue Champion's Tunic outfit will forever be tied to Breath of the Wild. The next game will probably bring back the classic look, or try something different again. But for now, fans can enjoy Breath of the Wild's design.