Revere Pewter (HC-172) is one of the most popular greige tones going, but Benjamin Moore sits at a premium price point in the UK and isn't always easy to get hold of. If you want the same warm, slightly green-grey neutral without the spend, you've got proper options.
The pick of the bunch is Crown Gentle Hush (LRV 57.9). At ΔE 1 from Revere Pewter, that's an imperceptible difference — sit a brush-out of each side by side and you genuinely won't be able to tell them apart. Crown is widely stocked, sensibly priced, and their Easyclean Matt is a tough, washable finish that's hard to fault for the money.
Runner-up is Dulux Shaded Stone (LRV 55.6) at ΔE 1.6 — still very close, and Dulux is on every high street, so colour-matching tins and touch-ups are dead easy. If you want a more premium feel without going back to BM money, COAT And Breathe (LRV 55.8) comes in at ΔE 2.3, which is still a very close match, and COAT's eco credentials and low-VOC formula are a nice bonus.
The "but what about" here: Revere Pewter is famous for shifting through the day — reading green-grey in some light, almost taupe in others. That chameleon behaviour is baked into the actual *colour*, not the brand, so any close-matched dupe will do the same thing. A ΔE of 1 means Gentle Hush will behave like Revere Pewter in every light you throw at it.
Practical advice: at LRVs in the mid-50s these all sit comfortably mid-tone — they're not bright, so a north-facing room will read them on the cooler, greener side, while a south-facing room warms them up nicely. Whichever you pick, get a sample pot, paint two coats on A4 card, and move it round the room before you commit. Order from one brand and stick to it for the whole job — don't mix Crown and Dulux tins of "the same" colour, as the tiny ΔE differences can stack up on a big wall.