The term "blue moon" comes from folklore. Different traditions and conventions place the extra "blue" full moon at different times in the year .In calculating the dates for Lent and Easter the Clergy...
No. The term blue moon refers to an extra full moon in a month or in a season, not its colour. but even though the term might not be refering to a blue colored moon, the moon can appear to turn blue...
No. Since the moon shines on one side of the planet and the sun shines on the other side, it wouldn't be a global blue moon. But it would be on the half of Earth where it is shinning.