Background matching: Researchers traced how zebrafish larvae blend into bright surroundings through background adaptation, identifying which cells in the eye and brain control it.

Tracing connections: Specialized cells in the retina signal the brain to control two hormones – raising levels of one that lightens the fish while lowering levels of one that darkens it.

Pinpointing the pathway: This work pinpoints cell types and connections, revealing how vision controls body-wide color changes – a fundamental response across some fish, amphibians, and reptiles – and opens up key mechanistic and evolutionary questions.