I can't help you with the red peas but I am also growing Colossus this year. It's a first time for me but I've been growing field peas a good while now and am willing to bet it's like Big Red Ripper and Big Boy. Those are pretty rambunctious peas that you can let sprawl or trellis. Southern Exposure lists Colossus as "One of the largest and best crowder peas..."
I've always done the Rippers in the corn rows after the stalks are pulled but last year I trellised one row just for grins and giggles. It seems like there were more peas on the trellised ones but maybe that was my imagination since I didn't weigh anything. There were three rows on the ground and one trellised.
The Colossus will be going in a raised bed once the currant occupants (broccoli, cabbage) are booted out, one row down each side. I'll be putting some tall stakes down each side with some baling twine stretched between to help keep the Colossus in bounds.
Can't help with the bush limas as I've tried a bunch and although I get pods, there's never anything in them. I found lima success with a climber, Alabama Blackeye Butter Bean.