Bill,
If I am understanding the situation, you are saying that the bike is "over heating" because the temp display is saying "Hi", correct? It is not barfing coolant yet, just displaying "Hi" warning?
And, when you are testing it you also say the fans are kicking on at the right temp, and blowing air through the radiator properly (from front to back), correct?
If the engine temperature is being properly maintained at normal levels while riding the bike, and 165-175 are normal levels AFAIK, then this means the thermostat is operating correctly, the water pump is moving coolant properly and the radiator is shedding the coolant heat correctly.
You've said the fan is kicking on and blowing hard, so that should cause the coolant temp to drop a short time after it does kick on, but you say that the temp keeps climbing then, which gets back to the fan not blowing enough air or the radiator not shedding enough heat.
I think that the change in coolant color indicates that the shop is pulling your chain here. Something happened while they had the bike and they are not telling you about it. You weren't supposed to notice that. Wonder what kind of **** is they put in there? Might be worth doing a drain flush and fill with a known quality coolant. I'd do that before I ever set foot back inside of that shop if it were me.