Bear with me. The default priority custom field in Asana contains High-Medium-Low.
Apart from the fact that they should not have colored them all (but only color High), I believe having a Medium and Low priorities adds complexity where things used to be simple.
Something is usually either urgent, or is not. It is a high priority or a normal one. And, for the sake of clarity, when something has a default value, use an empty value! Your Asana project will be clearer, with less words and colors, and the actual high priorities will pop on the screen.
My revised version of the priority field? A single value « High » in red. Nothing else.