Often the moon is red as it rises. When the moon is closer to the horizon, its light must travel through the maximum amount of air to reach us. The gases in the Earth's atmosphere scatter the blue shades of light, so it does not reach us; instead, we see the red light. As the moon rises, it gradually loses its red color and returns to its familiar silver/gray tone because when it is higher in the sky the light does not have to pass through as much air to reach us.
This is why the sun rise and set are also red or orange. The sky is blue during the day because the air scatters the blue light evenly.