The tile installation was grueling and I
would like to know if there is a PRODUCT on the market that will fill
the scratches and blend in with the tan color of the Travertine tile.

Unsanded colored tile grout. Blend a lighter and darker shade of tan to
get a close color match. If you grout all the craters (if it is the usual
cratered travertine) in the whole floor this grout fill wouldn't even be
detectible.

You could also use clear epoxy mixed with dust ground off a scrap tile.
But that may wear differently than the original stone and likely show
later.