Although some people wait for the Moon to actually turn blue this night, the name of the phenomenon has nothing to do with color. The term "Blue Moon" simply refers to the event when the full Moon appears twice in a single month.
The occurrence is possible due to the difference between Moon's (29.5 days) and Earth's (30.4 days) cycles. Eventually, this gap leads to the full Moon appearing twice in the same month: on the 1st or 2nd and on the 30th or 31st. Hence, the Blue Moon happens every two to three years.
As for the Supermoon, the term describes a full Moon in the point nearest to the Earth, when it looks approximately 14% bigger than when it is farthest from the Earth. The Supermoon occurs three to four times a year. Thus, the Blue Moon and the Supemoon are different phenomena that can happen at the same time, just like tonight, but quite rarely: only 3% of full Moons are blue Moons. Moreover, the two phenomena coincide irregularly, however, on average it occurs every 10 years (20 max). The next Super Blue Moon will happen no sooner than in January and March 2037.
Check out Sputnik's gallery to find out what the Blue Moon looked like from different locations of the planet!