"Pink" moon is a nickname (one of several) for the April full moon that signifies that Spring is here!

The moon that we will see between Thursday night and Friday morning will not look pink, it will look like any other full moon.  The April full moon simply brings forth the flowering buds of trees and re-birth that springtime offers.

NJ.com says that other nicknames for the spring full moon include "egg moon, fish moon and the sprouting grass moon." 

Source: NJ.com