From Hollywood history history:
1937 Disney releases “Snow White and the Seven Dwarfs” – the first animated feature – using the new Three-Strip Technicolor process.
From Wikipedia,
Based on the German fairy tale by the Brothers Grimm, it is the first full-length cel animated feature film in history, the first produced in full color, the first to be produced by Walt Disney Productions, and the first in the Walt Disney Animated Classics series.