A Body with dark spots (spots may be absent in large adults)
B Outer margin of anal fin rounded, and anal fin with 24 to 29 rays
A Body without dark spots
B Outer margin of anal fin straight, and anal fin with 30 to 36 rays
It is a Blue. I have caught Channels that were a grayish, almost Blue color, mostly in Lakes & tanks / ponds. Small Channels in the river are usually olive with spots.
Also, remember that there are hybrids. I have caught a few Channels that even though their body said "Channel", there head sure did resemble (almost mimic) a Yellow (flat shovel type head).
I believe the largest Channel in Texas was a 36# out of Pedernales River a long time ago. I would have to check back on that though.