1978 Penny With Strange Color ?

One that comes to mind is improper cleaning with soap and too hot water.
John1

All of these "strange"color postings are best explained as "environmental damage"
Some can be attributed to being buried outside for a bit, some can be attributed to sitting on the ground for a bit, some can be attrbuted to being in a carwashort drain for a bit, or a fountain that chlorinated, or a pool, or washed with detergent in a washing machine, or stored in a container with a high sulfur content, or in a car paint booth operators pocket, or in a cement workers pocket.
Literally hundreds of chemicals a coin can come in contact with and change color, even a cent sitting in a urinal bowl and they bleach it to clean it and don't notice the cent there and get it out.
There's also high temperature and low temperature changes and humidity as also factor as well as a layer of dust and whatever contaminant makes up that dust and sunlight.

If you want take some common cents and run some experiments simulate a few environment conditions and see the results. Pinkish cents are usually soda like cola or toilet bowl cleaner that does it and makes them a dull pink color.

Unless you have a means of proving the metal composition is wrong then it's going to be an after minting environmental cause and either toning or corrosion, or a combination of the two.
In some instances it can be electroplating, also not an error but after minting damage.

Many possibilities on how that happened.
1. Was in a pocket of a person that got electricuted in prison.
2. Was in a place where high humidity got to it
3. Someone heated it to see what it looks like hot.
4. And many other possibilities.

Thank you I really like the color so I will keep it

"Rainbow" toning is a hot commodity right now. With lots of unscrupulous people trying too fake it on coins. Yours looks real, and would add a little value to the right collector. But if you like it, keep it. I would suggest putting it in a 2x2 flip to protect it. I could continue to tone if left exposed to the environment, and may eventually end up brown.

That's a beauty!