Even if you don't have a dozen children, cups are an issue. Often no one remembers which cup is his and gets out a new cup. Or uses his sister's cup. To which a dispute arises.
Either way, a mom is left dealing with tons of dirty dishes or tons of bickering. Neither of which appeals to any momma.
The solution at my house was a long time coming. We had to endure one color for each child (and he could only use his own color) and each child has one spot where his cup belongs before we found the magic bullet. Rubber bands!
It's really simple. You buy a bunch of rubber bands. Each child puts a rubber band around the midsection of his cup. The trick is this: Each child has a different color rubber band. The cup with the red rubber band is Johnny's cup because red is his color.
If you have more children than rubber band colors, you simply buy rubber bands that are about 1/4 to 1/2 inch wide. Then you use an ink pen to write the child's name on the rubber band. Then each cup has the owners name on it.
The rubber bands can be used again the next day.
Simple. Clear. No confusion.
I no longer have meltdowns because of cups.