Question: why do leaves change color in the fall?

Dimitar Shterionov answered on 14 Nov 2018:

Usually the leaves are green because they contain chlorophyll (chlorophyll is the substance that transforms sun light into energy for the plant to live). In the autumn, however, when the weather changes the plants stop their food-making process and the chlorophyll breaks down and leaves change their color.

One thing I noticed when I came to Ireland is that due to the rain and the small amplitudes of the temperatures in the summer and the winter, the grass and a lot of other flora is constantly green, unlike in other countries like Greece or Bulgaria, where in the autumn the grass becomes yellow and dries out.