Have you ever heard the saying "once in a blue moon"? Rejoice cause tomorrow night it'll be actually a blue moon!
Well, kind of. Cause the definition is that of the third full moon in an astronomical season, or more commonly the second full moon in a month that already had one.
The even though is kind of rare as the saying implies, just consider that between 2001 and 2099 there are only 41 events, and next ones after tonight will be 21 May 2016, 18 May 2019 and 22 August 2021.
As for the blue part...that actually only happens if an eruption releases a lot of particles in the atmosphere that shield certain wavelenghts. So probably it won't be blue. Or hope it won't be, cause it is something is wrong with our atmosphere(or you're dying under a volcano).