Why is it called a pink moon?
The name can be traced back to North American aboriginal peoples, who referred to the full moon in April as a pink moon after a type of wildflower that blooms early in the year, helping to signify that spring has arrived.
The moon doesn’t actually appear pink in color.
http://www.cbc.ca/news/technology/4-facts-about-the-pink-full-moon-1.1313175