Blue Zone is the hottest part of the flame that is where the flame has the most Oxygen and you are getting complete combustion. It is about 1400 degrees Centigrades. The Reddish part (Non - Luminous Zone) is the coolest part, about 800 deg C.
When you give your item to the USPS for delivery, it accepts your item and starts the process of delivery. Transit is a part of the shipment delivery process. When we say that the package is in the transit or in transit to the destination, it means that the package is on the way to the delivery.