The kit first worn by Argentina in their official debut v Uruguay in 1902 was a light blue shirt. On July 2, 1908, Argentina debuted the light blue vertical stripe on white jersey, when the squad played vs a team formed by Liga Paulista players at Velódromo Paulistano. That striped jersey has remained as the official kit since then.
https://en.wikipedia.org/wiki/Argentina_national_football_team

