A couple of days ago, I picked up these two $1 chips from Rampart Casino in northern Las Vegas.
Note the difference in inlay background color. The first one is a reddish-brown inlay, while the 2nd one is a lighter brown without the reddish undertones.

It's not a matter of fading or sunlight. There were some of both versions mixed together in a the dealer tray at blackjack.

The reddish one appears in the ChipGuide, but no entry of the lighter brown inlay.
In TCR, there's one brown $1 H&C chip listed, with the TCR # of the reddish-brown inlay, but no 2nd listing of another brown $1 chip at Rampart.

Another factor -- in the NGCB report, there's a Rampart $1 chip, only described as being brown, with a GPI (H&C) mold, approved in June 2025. Could the lighter brown inlay be a reorder of $1 Rampart chips, except that the inlay changed slightly?

And a definitive difference -- it's hard to see with the naked eye, but the graphic behind the $1 symbol is different. You'll be able to see this difference with the two chips side-by-side.

I'll submit the new one the ChipGuide and TCR in a few days.