5 COLOURS IN THE AUTUMN PALETTE

1 BROWN

COMPOUND: TANNINS

These compounds are waste products of metabolic processes within the leaves. While they are always present, only when other pigment levels, such as chlorophyll and carotenoids, are low are these visible as brown hues.

2 RED

COMPOUND: ANTHOCYANIN

As chlorophyll is broken down, anthocyanins are produced. These produce leaves of red, purple and pink that are displayed on trees such as maples, oaks and sumacs.

3 ORANGE

COMPOUND: CAROTENE

Sugar maple trees turn a vibrant orange colour in autumn due to the increased concentration of carotene pigment. While chlorophyll diminishes with reduced light, carotene doesn’t. This increases its concentration, and when combined with anthocyanin, different shades of orange are made.

4 YELLOW

COMPOUND: XANTHOPHYLL

This pigment is in a group called carotenoids, along with carotene. However, this pigment contains more oxygen and produces a light-yellow colour. Some of the trees that display xanthophyll in autumn include birches, beeches and aspens.

5 GREEN

COMPOUND: CHLOROPHYLL

Evergreen plants continue to photosynthesise during autumn. They retain their green colour yearround by continually producing chlorophyll – the green pigment that absorbs sunlight.