Color of CoolGard II concentrate and radiator hoses?

I changed coolant in my 2720 this morning and used a 50:50 mix of distilled water and CoolGard II concentrate. My factory fill of coolant was a nice bright green whereas the CoolGard is a very pale yellow, It almost resembles the color of hydraulic oil. I know color shouldn't matter but having a nice super bright green color to the coolant makes it easy to spot leaks or overflows. I doubt you would even see this stuff if it leaked.

Anyone have the same observation? Is all CoolGard yellow?

Also, I carefully measured the amount I drained (1 gallon) and was able to put about 1 cup shy of a gallon back in. I ran the tractor to ensure I didn't have any air bubbles but I don't think the thermostat is opening. The top hose is very warm, almost hot but the bottom radiator hose is almost cool to the touch. I ran the tractor for about 20-mins... running it at 2000-2500 RPM, up hills, down hills, etc. The only load is the weight of the loader and 800 lb. ballast box. Still the bottom hose is cool to the touch. Without a temp guage on these tractors it is really hard to tell what the engine is doing. I don't mow with it so other than some occasional loader work and driveway maintenance the only time it gets driven hard is during the winter when plowing and running the 54" blower.

Any suggestions? Shouldn't my lower radiator hose get hot at some point?