With leaf fall comes Autumn colour, we can not have one without the other. The first tree to show its amazing colour is the Cherry (Prunus spp.) on the main lawn and the last will be the Hornbeam (Carpinus betulus) and the Beech (fagus sylvatica).
Leaf colour is part of the process mentioned in the blog entry 21st September, "They All Fall Down", so here is the next bit of education for you about leaf autumn colour!
When days grow short and nights cool, deciduous trees decrease chlorophyll pigment production allowing other pigments present in the leaf to become apparent, resulting in autumn colour. These other pigments include carotenoids that are yellow, brown and orange. Anthocyanin pigments produce reds and purple colours, though they are not always present in the leaves but are produced in the foliage in late summer when sugars are trapped in the leaves after the process of abscission begins.