All smallies share the barred coloration. I've caught little creek smallies and have watched their coloration go from a solid golden-olive to a distinctly marked appearance while removing the hook from their mouth. I think stress plays a big part. Similar to a sailfish "lighting up" with bright blue marks during feeding (used to confuse prey, which are sensitive to blue-green color spectrum) and appearing a uniform black when landed. All fish do this. Some are better at adapting color for camo purposes, and one of the best in freshwater is the rock bass (black perch, red-eye).
Depth also plays a role, due to exposure to sunlight. Most of the deepwater largemouth i catch are pretty blandly colored, while shallow water fish are more visibly marked. This is just my opinion, but the same phenemon occurs in clear water bass (darker markings) vs murky water fish (paler markings), so i'm assuming the exposure to higher light levels play a role.
Being marked probably has ambush/concealment advantages, too. A highly marked fish in clear water benefits from a broken-up silohuette against grass, weeds, etc which grow better in clearer water whereas a bland fish can use murky water alone as concealment.
Chris
|