In most cases inserts are unique to a casino.
I know of cases where a casino made a high denomination chip only to learn the color and inserts were too close to a low denomination chip from another casino. They destroyed them and made new ones. Rio is the last one that comes to mind.

A good cage person can spot a foreign chip in a rack of chips from across the room even if the inserts are close.

I am willing to make a little bet. Show me a rack of red chips from LV and I will name 50% or more of them while they are still in the rack. The 10 chips on both ends of each barrel don't count. On a good day, I could name all of them

Grifters have a bad habit of painting $1 chips to match $100 chips and sticking a couple in a stack.
They are usually nailed on their 2nd attempt.