For the sake of appearance, colour can make a world of difference. In tropical rainforests, a bright upper canopy, rich in blue and UV, and a dark understorey, rich in green and orange, contrasts two distinct light environments.
When discretion is important, bright greens blend better in the upper canopy, whereas dark browns have the advantage in the understorey.
When advertising an invitation to treat, as it were, bright blues glow advantageously in the upper canopy, whilst yellow and red signals optimise conspicuousness in understorey. The Hairy Red Pittosporum P. rubiginosum ssp. Wingii, of Australia’s tropical rainforests, is an excellent example of the latter.