Answer
Camouflage allows the gecko to hide from predators in plain sight, making it easier to stay unnoticed and hopefully uneaten.
Work Step by Step
Genes coding for the various skin colors, textures, physical shape, and control would have gradually adapted over many generations. As each gecko with slightly better camouflage was able to survive and potentially sire more similar geckos, these genes would be passed on. Geckos with an array of different camouflaging adaptations likely bred with each other, mingling and refining these traits over time.
