In some areas, each autumn, leaves on all plants except evergreens change color. These yellow and orange colors were inside the leaves ever since summer. However, the colors weren’t visible because of too much green chlorophyll in the leaves. The chlorophyll slowly breaks down and vanishes when the temperature begin to drop. Where it’s clear and cool you’ll see another color— red. In warmer climates where the sky is cloudy, you wouldn’t see this color.