because you seem convinced that seeing a spectrum of colors is not a normal event caused from the optical illusion of light passing through and reflecting off of water droplets.
Actually it's not an illusion and it's refracting, not reflecting. No, I'm not trying to insult you, just pointing out the facts that are misconstrued, since optical theory is something I studied long ago, although I don't remember half of it any more. Light passes through the water droplets or vapor and a prism effect results when the different wavelengths refract, or bend, at different angles which separates them into visible bands of colors that make up normal sunlight. You also only see part of them, rainbows are actually circular, you only see part due to the sun's position in relation to your own. In addition, there are other wavelengths like ultraviolet and infrared that you see very vaguely if at all. It's not an optical illusion, you're seeing what's really there, different wavelengths of light.
An optical illusion is seeing something that is not there, like an old favorite of mine. If you hold two fingertips a couple of inches from your nose and bring them slowly together you'll see a single section of finger form with a fingertip on each side, floating in midair. Or loosely hold a pencil horizontally a couple of inches from one end and shake it up and down. It will seem to flop around and bend as if it's made of rubber. Longer pencils work better, and a ruler will work too. Those are optical illusions.
Back on topic, UFO's...I can't say for sure if they were UFO's or what, but I've seen a couple of things that were highly unusual, to say the least. On one occasion about two years ago while using my telescope in the front yard, nothing there but open sky, a light sitting still and looking just like a star blinked three times in a couple of seconds and was gone. No movement, no sound, nothing resembling a physical craft, just a light I noticed for several seconds, then it blinked 3 times and was gone. Not looking through the scope, just looking around to see what else I might want to point it at.
Years ago, before most of this year's college graduates were born, I watched a light, again no definite shape of any craft, just a light, zoom across the sky incredibly fast, take a distinct hard left as if it bounced off a wall, then a hard right as if another bounce, then zoomed off into space. All this in 3 or 4 seconds, in the middle of the Atlantic. No, I'm not sure if it was in the Bermuda Triangle, though we did pass through it that trip with nothing more interesting than a half hour with no power whatsoever then it was back. This moving light happened around the same time, or the same night at least, and went well over halfway across the sky in 2 seconds. Planes take 3 or 4 minutes to move that far...Air force fighters...
It's anybody's guess what either one was, I'm not sure, but after all I've read over the past 40 years I'm pretty sure we're not the only beings who have seen this planet from above...and after looking at the Hubble Telescope website and seeing the pictures of the hordes of galaxies out there and figuring on billions of stars each, it's not easy to see us as the only intelligent creatures in the universe. And if there's even a hint of fact to the multitude of educated guesses on that issue, I'd bet somebody out there can make it across the light years to check us out.