If you want Swiss Coffee in a Dulux tin, go with Dulux Lambs Wool. It lands at ΔE 1.2 from the original — anything under 1 is invisible, under 2.5 is very close, so 1.2 means you'd struggle to tell them apart on the wall. That's about as good as a cross-brand match gets.
Why does Swiss Coffee inspire so many "what's the match" questions? It's one of Benjamin Moore's most loved soft whites — a warm, creamy off-white with just enough body to feel cosseting rather than clinical. The catch is BM availability and pricing in the UK can be patchy, so people quite reasonably want it from a brand that's easy to get mixed up at the local merchant. Dulux fits that bill nicely.
The runner-up is Dulux Quilted Calico 4 at ΔE 1.4. It's still a very close match, but it sits a shade lighter — LRV 82.4 versus Lambs Wool's 76.4. That six-point gap matters more than the small ΔE difference suggests. If your room is north-facing or short on light, Lambs Wool's slightly lower LRV gives you that creamy warmth Swiss Coffee is known for. If you want it to read a hair brighter and airier — a hallway, say, or somewhere you're chasing every bit of light — Quilted Calico 4 nudges it that way.
The "but what about" here: don't trust the chip under merchant lighting. Both of these are warm whites, and warm whites flip character depending on the light and the colours around them. Get a sample pot of each, paint two A4 patches side by side, and live with them for 48 hours across morning and evening light before you commit.
If you're matching to existing Swiss Coffee on a wall — touching up rather than redecorating — be aware sheen and age will throw the comparison off, so test against a freshly painted patch, not a ten-year-old skirting.