Answer:
To save itself.
Step-by-step explanation:
The color patterns of the frog and its lack of color on the ventral surface allows the frog to protect itself from their predators because the frog changes its colour and the predators are unable to see them. The color patterns of frogs and their lack of color on the ventral surface allow frogs to escape from their predators. If the frog does not change its colour, the predators will see them and the frog will be catch by its predators and feed on them so this is the reason that frog changes colour or the presence of colour patterns.