|For trout, the pigment of their flesh and outward coloration is
largely influenced by their diet. For example, carotenoids (color pigments) found in crustaceans such as; crayfish
and freshwater shrimp are largely responsible for the red, pink and orange pigments that you find when examining fish
flesh. Trout that do not have access to these types of food items would typically lack this pigmentation.
Hatchery trout are typically more bland in coloration in comparison to their wild cousins. This is primarily due to
the fact that they are fed a formulated diet that does not include the many of the food items that provide the color
pigments found in nature and more readily available to a trout foraging in the wild.
Secondary sex characteristics such as, the kype on the lower jaw of a large male trout will develop in older and
larger trout regardless of their origin. These characteristics are due to physiological changes in the fish as it
matures and are not related to specific items in their diet.
From your description, it would appear most likely the trout you caught originated from a hatchery.