When low on the horizon, the light from the moon must pass through the maximum amount of the earth’s atmosphere. The dust particles, smoke, haze and water vapor all tend to scatter the light of longer wavelengths. This leaves the shorter wavelengths, such as reds and oranges, as the only colors able to pass through. Last nights rising moon was a good example of this. Not a great hand-held image, but this was taken very spur of the moment.