Hello I will help you with your question,
The coolant fans are turned on at 217 and off at 190 so you are in the correct range for the gauge to read in the mid point. The engineers like for the gauges to read in the middle for normal operation as it seems to give most operators confidence.
Coolant when mixed 50/50 with water and pressurized to 15 psi will boil at 253 at sea level. This would be overheating and your gauge will go to the red at 245
Let me know if you have further questions about this