2005 dodge caravan. why is coolant looking like red mud?

Red mud is probably rust. You need to power flush your engine until the water runs clear and then use proper 50/50 coolant and add some good rust preventative.

I would use the green all engine types coolant from Prestone.

I must meet your mechanic! Gm runs orange (primarily) Or yellow (Universal). For future reference if someone tries to argue with you and stick green in...please don't. Green will eat that radiator and everything attached to it

I said green because that is what the universal coolant looks like to me. Green coolant does not eat up anything . Some people say it can react with other types of coolant but that is it.