eli5 Why do plastic products sometimes have a clock sort of thing on them

Question

The title. Also why does some cardboard packaging sometimes just have random colors in one small area

In: Other

Answer 1

Both of those are for quality control checks.
The clock tells you when the plastic thing was made. So if the plastic part factory starts discovering a lot of “bad” parts they can hopefully use that information to track down the cause.
The “random” colors are to check for problems with printing. They’re usually setup to let the printer check that the darkness of each color is correct, and to check that the different printing steps all align with each other correctly.