Causes of different colors

In spring and summer when there is plenty of sunlight, plants make a lot of chlorophyll. In autumn when it starts to get cold, some plants stop making chlorophyll. Instead, those plants break down chlorophyll into smaller molecules. As chlorophyll goes away, other pigments start to show their colors. The plants genetics also play a major factor. Hopefully, I answered your question and remember Happy Growing and Free your mind one puff at a time.