Is there a rainbow moon?

Excuse me, but could you elaborate on the concept of a "rainbow moon"? I'm familiar with rainbows and moons, but the term "rainbow moon" is rather unconventional. Is this a celestial phenomenon that has been observed, or is it a fictional or metaphorical construct? If it's a real occurrence, could you describe the conditions under which it might appear? And, most importantly, have there been any scientific studies or theories that explain the existence of a rainbow moon?