All the halos I get are the same whether it's from the sun, a lamp, or the moon. They have rings of color in the following order: blue green red. Is this a defect with my camera/lens?
Nothing wrong with your camera/lens. It's probably a flare ring. Can avoid it using a hood, or using your hands to shield outside light from hitting the front element of the lens. If the light source is in the picture, you can try stopping down the aperture (use a larger numerical value, eg f8 instead of f4).
