If you want to trace the brand colour name, if there's a factory specification card with the bag this would probably include a factory colour code. An AI search should be able to identify the official name. Ditto, if you enter the model and year of manufacture it may be able to list the then available colours.
That said, I'm not sure how having the official colour name will help if unless this was stated in the item description. Otherwise, if it's a good match for the photo in the listing, I imagine the authenticators would treat the colour as being as described.
