Is it a sign when the moon turns red?

A red moon can come from 2 sources. When the full moon rises close to the horizon, it is generally a reddish color because we're looking at it through the smog and pollotion that is in the air.

The moon is also a bronze-red color when there is a full lunar eclipse for the exact same reason. The sunlight striking the moon during a total lunar eclipse passes through the earth's atmosphere, which causes the moon to look reddish.

If you see a red moon on any other occasion, you might want to consult an eye doctor.