Hi there, Aishapatel!
Leaves have a substance called Chlorophyll in them, which makes them green. As summer turns to winter, it gets cold and the leaves die. As the leaves die, the chlorophyll goes away, the leaf begins to change color.
I hope I helped!
(P.S. Brainliest Answer please? I got to Virtuoso but Brainly just removed it and I don't know why, but now I have to start over. :()
