What are the different colored circles on yogurts for?

Question

A bunch of random colored circles on the back of yogurts and stuff, I was just wondering what they're there for.

Answer 1

That's from where the plastic is printed at. So the printers know the colors stay in place and stay vibrant.

?? sounds good ??

Answer 2

It does look like the color proof spots used in printing, but usually they are not printed on the final product, just the proofs.

When I saw the question, I glanced down at the yogurt carton on my desk and there they were! Funny I never really noticed them before.