I did a search but couldn’t see any mention of this.

Got given a new style boarding pass this morning at the First Wing at LHR T5. The front is exactly the same, but paper feels thicker. The back is a grey/brown colour with the speedmarque and “The First Wing” branding with a wavy line design underneath (have tried to upload a photo, hopefully it works, sorry for bad photography and scuffs to paper where I removed my baggage receipt).

Looks a little classier than previously so thumbs up to BA.