If you've fallen for Benjamin Moore Simply White but want to spec it in Dulux — usually because the trade counter round the corner stocks Dulux and not BM — New Meringue is your answer. It lands at ΔE 0.8 from Simply White, which is comfortably under 1. At that distance the difference is imperceptible to the human eye; you could paint one wall in each and nobody would spot the join.
New Meringue carries an LRV of 83.8, so it's a proper soft white with a warm, creamy edge — exactly what makes Simply White so popular. It's not a stark, clinical white. There's a barely-there yellow undertone that keeps it from going cold or blue, which is why it flatters warm-lit rooms and pairs beautifully with natural wood and brass.
If New Meringue isn't on the shelf, Vanilla Mist 4 is the next best thing at ΔE 1.2 and LRV 85.4 — a touch brighter and still very much in the same family. Both are solid swaps.
The one thing to flag: a colour match tells you the two paints *look* the same, but the finishes and bases behave differently. Benjamin Moore's Regal Select and Aura have a particular dead-flat, ultra-washable quality that Dulux's standard ranges don't quite replicate. If you're matching for budget or availability, you'll get the colour bang on — just don't expect the identical film and washability. For trim and high-traffic areas, spec Dulux's tougher finishes (Diamond Matt or the eggshell) rather than standard vinyl matt.
My advice: order a New Meringue tester and brush it out on a couple of bits of A4, then move them round the room across the day. Warm whites shift more than people expect under changing light, and you want to see it doing its thing on your walls, not under a shop spotlight.