When you spill water or spit on your computer screen you'll see a rainbow. What is the reason for this?

Pray tell, how do you spill water on an upright computer screen and do you really spit on your computer screen? I've wanted to do that a few times but was able to hold back!

I am not sure of the answer, but this is one of the funniest questions I've read. I'm eagerly waiting to hear the answer.

Have you NOT ever taken a drink of something right as you read or heard something funny...you are laughing so hard that you can't swallow which ends up with you spraying your entire mouthful all over your screen and EVERYTHING else that's sitting on your desk? Your lit monitor becomes the sun and your spittle becomes the moisture from the rain storm...voila...a rainbow.

"A rainbow is an optical and meteorological phenomenon that causes a nearly continuous spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere."

https://en.wikipedia.org/wiki/Rainbow

Well, if it's what I think it is, it's not really a rainbow. What you're actually seeing is the pixels of the screen magnified by the spilled water - the water droplets are acting as lenses. With old CRT screens each pixel was made up of a red, a blue, and a green dot, and since these are rainbow colors, I can see how someone would think it was a rainbow.

I don't know how this would work on LCD or flat-panel screens.

Try this (if you dare!). Put a drop of water on the end of your finger, then put your fingertip on the screen. You'll leave a droplet on the screen. Look through it, and look through it from different angles. See! A rainbow!

The water droplet refracts and magnifies the color pixels on the screen. Red, Green and Blue are the individual colors that you see because these are the primary colors of the TV/Monitor pixel array that, through varied brightness intensities, produce the millions of colors that we see.