Blue cats are also called fultons, humps, silvers by the riverrats

Flathead - blunt tail with no V, ugly mud color
Channel - distinct V tail, spots along the side
Blue - a rounded V tail, more like a U-shape, long flat anal fin

I see all three kinds in that 1st pic, take note of the diff in the tail between that big fish on its side (blue) and the one to its right (channel) and the diff in their anal fins