If the casino meant to change the chip, and made a minute change on purpose, then, in my book, it is a "different" chip.

If the manufacturer didn't get quite the right amount of a particular color into the recipe, and the chip came out a tad darker or lighter, then I don't bother......it is the same chip.

Things like an extra line thru a $$ sign, or slightly darker fonts don't make enough of a difference.

But hey, I like to collect 1 representative chip of each different issue from the casinos I collect. If I were a collector of a single casino, I can see where collecting 1 of every variation would be fun.

Ultimately it is up to the collector, and I like that about this hobby....it is personal preference!