Speaking of his voice actor, the man is Jack De Sena, a comedian. The only thing I recognize him from on his IMDB page is he was Jimmy Olsen on The Batman. I wouldn't know that because I jumped that show early on like the white chick of the Titanic. The guy should get more work, his job as Sokka is great, and probably a large reason why the character is so well-loved and relatable.
Sokka, obviously, fits in with the rest of his tribe in color. But that isn't Blue. Sokka and his tribe's main color is White. Sokka is a bastion of order, a main staple of White. It also works mechanically, because Waterbending can heal (Damage prevention and/or lifegain) and is very defensive in fighting. Sokka is Blue too, his creativity and intellictual streak show in that, but his main color is White.
Sokka is an awesome character, relatable to most nerds in a lot of ways, and just plain cool. He doesn't develop much over the seasons, but I'll track what does develop.