Question

Which color of moon means once in a very long time?

Answer 1

The color of moon that means once in a very long time is a blue moon. A blue moon is a rare event that occurs when two full moons occur in the same month. This phenomenon is usually only seen once every two or three years.

Answer 2

There is no particular color of the moon that signifies "once in a very long time." The color of the moon can vary depending on atmospheric conditions, such as variations in the amount of dust or pollution in the air, but this does not necessarily indicate rarity or infrequency. The term "once in a blue moon" is used to describe an event that is rare or uncommon, but this phrase refers to the occurrence of two full moons in a calendar month, rather than a specific color of the moon.