Autumn is a time when, probably more than any other, we’re aware of colour in nature. At the risk sounding like Philomena Cunk….but what is colour?
The greenness of a leaf isn’t something inherent in a leaf - it’s a sense perception in the brain. Sunlight hits the leaf, chrolophyll absorbs certain wavelengths of light to produce sugars by photosynthesis. The wavelengths which aren’t absorbed are reflected. This light hits our eyes when we look at a leaf, - the brain interprets this with a sensation of “green”.*