Consider the following scenario

In a muddy lake environment, some fish have brown scales most fish, however silver scales predators. Have a harder time seeing the fish with brown scales.
Which term best describes the brown scales

in this scenario?

The term that best describes the brown scales in this scenario is "camouflage." The brown scales help the fish blend in with their muddy environment, making it harder for predators to see them. This provides the fish with a protective advantage in avoiding being eaten.