The bag in the pictures is authentic. Seller is very reputable.
I can see your confusion. Not long ago I noticed this bag too on Boutique Patina's site (I am a sucker for the caviar Diana) but going back to check I am noticing that the first image color on your SnobSwap link looks different compared to the store's
original website listing image, or even the other images in that same page. Sometimes, online platforms like Tradesy, Shop-Hers, will "clean" or totally Photoshop sellers' thumbnail images, white out backgrounds, etc., to make uniform to their homepages, so I would go with the color ways of the original listing. Based on the original listing it looks like light beige. Vintage beige came in two types - light beige and dark/camel beige. Clair wasn't released till later on. The main difference between BC and LB is that BC has pink undertones, LB does not. You won't find a vintage in BC.