Sometimes, the moon can look blue. When a volcano erupts, the moon can look blue. In 1883, Krakatoa exploded. It was a big volcano. There was a blue moon almost every day.
The moon can also look red. This happens when the moon is close to the ground.
Difficult words: full moon (when you can see the entire moon), volcano (a mountain which can sometimes explode), erupt (to explode).