I'm not sure if pink cloud and overconfidence are intertwined. I always felt that the "pink cloud" is a mix of emotions, like 1) happiness that one isn't drinking, 2) relief at getting past withdrawal, 3) euphoria that the beast is finally off one's back, and 4) hope that we can be the person we want to be.
I remember feeling just so dang happy that I could pass the days without drinking. I wasn't thinking about the future, or about relapse. I just felt like a weight had been lifted from my shoulders.