Two of the trout had white flesh while the third had orange/pink flesh.
Not as pink as the (landlocked) Dolly Varden I used to catch in Alaska,
but distinctly _not_ white.

Coincidentally, the 'orange' fish had a belly full of bugs while the two
'white' fish had very little in their stomachs.

I am fishing several rivers, of which one has a very good population of
Gammarus. The trout here have a very pink flesh! Most of the trout caught
are full of these little shrimp, some do have up to 200 in their intestines!

My assumption, and I'd like to think the obvious one, is that the
'orange' fish had been in the creek substantially longer than the
'white' fish. Long enough to learn how to eat and even thrive in the
wild.

It could also be the case, that they feed on different kinds of food.

OTOH, I figure that the 'white' fish were relatively new to the
stream and hadn't figured out how to eat & thrive in the creek.

I've often seen that newly stocked trout are very skillful in catching
minnows. They are probably not clever enough to search for larvae and
nymphs, but fast and aggressive so they will feed on smaller fish.

Daniel