Maglia rosa
From Wikipedia, the free encyclopedia

The maglia rosa (from Italian: "pink jersey") is awarded to the leader of the General Classification (GC) at the Giro d'Italia. The leader of the GC is the rider who has the fastest time when all the stage results are added together. The final leader of the GC is judged to be the overall winner of the Giro. It is akin to the maillot jaune of the Tour de France or the Jersey de Oro of the Vuelta a España.

The color pink was chosen in honor of the founding newspaper, the La Gazzetta dello Sport. La Gazzetta is known for the bright pink paper that it is printed on.

And yes, 1931 was the first year the leader wore pink.