Lizard tails are variously colored to confuse or evade predators, depending on who the lizard killers are.
To have a predator think that its tail is its head, and so facilitate evasion, lizards with weasels or snakes as nemeses have vivid blue in their tails – a color which both snakes and weasels can see. In lizard populations where snakes are the main enemy, lizard tails reflect ultraviolet, which snakes can detect but weasels cannot.
Where birds are a threat, lizard tails are a cryptic brown. As birds have keen sight, the best a lizard can do is have a camouflaged tail.
“Nano-particle pigments in skin produce anti-predator tail coloration.” ~ Japanese zoologist Takeo Kuriyama
The precise arrangement of microscopic light-reflecting platelets creates the requisite visual effects which appear in lizard tails. Creative pigmentation techniques are employed by many animals and plants to create specific looks, some of which are quite dazzling, or rather drab, depending upon what works best for an intended purpose.
Such specific adaptations illustrate how localized coherence attunes the traits of organisms to provide at least fighting odds of survival.