Older movie was in color, probably technicolor, had a bit of a Cool Hand Luke feel to it, but I didn't see enough of the movie.
Starting point I saw was a cowboy guy robbing a bank alone, but walks into the vault and the teller slamming the door on him. He may have done it on purpose, as he lights a match in the dark vault, grins and the match goes out. Next we see a boat arriving at a prison in the middle of a swamp, where the fat warden gives a welcome aboard speech about how it's not even worth escaping based on the surrounding dangers. Place looks like the chain-gang era of thing with wooden huts and bunks.
I suspect this is an escape movie, but I didn't get much more from there.