Yes, I'm still running with swamp water in the tank, but no signs of overheating, etc.
When I first brought this to the dealer's attention they added some coolant and I noticed that the color of the fluid in the tank was a little bluer.
I happened to quickly check the coolant yesterday afternoon and it seems that the slight bluish tint that had been present appears to have vanished and has reverted back to the original color I noticed when I first posted.
I need to actually withdraw some coolant and take a closer look at the color. I'll post again when I do that later today.