Penny Color ? Bad Or Good ? 1969-S

Its just toning, it happens when environment act on the coin,it just probably got some air and moisture into it. They can be very colorful! I keep them just because they look nice. No premium or error just natural toning of the coin.

umm some toning can bring in a much bigger premium some hurts the price its all about lets call it curb appeal! I sold a 1990 pcgs ms67red for $58 on the same auction I sold a 1990 pcgs ms67 red with a circle rainbow tone it was cool it sold for $145

Natural color. Looks pretty.

And yes, toning can increase the value of the coin to some collectors, but from what I understand, it is a smaller market of buyers who would be willing to pay more for the toning, and it is harder to nail down a value to toning alone.

First of all, this is a proof set - not a mint set.

Second, these coins are often more valuable for the toning, BUT...

Leaving coins in such sets CAN over-tone the coins rendering them worthless over too much time. They are like a cake - they have to come out at just the right time to stop the progression of the color.

When is the right time? Ask somebody who knows...really. I don't. But it is an important point.

When the coin comes out, it needs to be protected. I recommend slabbing if the coin isn't spotted and will grade at least PF68.