Why do vine leaves turn red, yellow or orange in autumn?

In autumn, when temperatures drop and the light decreases, the vine prepares for winter and the coming of the cold.
Chlorophyll, which is the source of the green color, starts to degrade and finally gives way to other pigments, such as the carotenoids that color the leaf in yellow-orange and the anthocyanins that provide colors ranging from red-orange to blue-purple.
Thus, depending on the brightness and the proportions of these pigments, the autumn leaves will take on one shade rather than another, until they become completely brown, the last stage before their fall and winter.

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