 Chlorophylls degrade into colorless tetrapyrroles known as nonfluorescent chlorophyll catabolites.As the chlorophylls degrade, the hidden pigments of yellow xanthophylls and orange beta-carotene are revealed.These pigments are present throughout the year, but the red pigments, the anthocyanins, are synthesized "de novo" once roughly half of chlorophyll has been degraded.