How could you design an experiment to show that a species of small fish has the ability to evolve a camouflage color pattern?

To design an experiment demonstrating a species of small fish's ability to evolve a camouflage color pattern, first, establish two controlled environments: one mimicking their natural habitat and another with a contrasting background. Introduce a population of the fish to both environments and allow them to breed over several generations. Monitor and record any changes in coloration over time, comparing the fish in the different environments. Finally, analyze the genetic variations associated with color patterns to confirm evolutionary adaptations linked to camouflage.