If you want Benjamin Moore Chantilly Lace in a Dulux tin, Dulux White Cotton is your answer — it lands at ΔE 0.5 from the original, which is well below the threshold where the eye can spot a difference. Put the two side by side and you'd struggle to call which is which.
White Cotton sits at LRV 87.6, so it's a properly bright, clean white — exactly the brief Chantilly Lace was written for. That high reflectance is what makes it sing on ceilings and trim, and why it reads as crisp rather than creamy. No yellow, no grey skew — just a clean, near-pure white.
If you're after the Dulux Heritage line instead — better depth of pigment, a lovely flat matt, and a more premium feel for trim and walls — then DH White is the one to reach for. At LRV 84.7 it's a touch softer than White Cotton, and the match comes in at ΔE 1.2, still firmly in "very close" territory. The slightly lower LRV means it's a hair gentler underfoot in bright south-facing rooms, which some people actually prefer for walls.
The usual "but what about" here: don't assume a perfect ΔE means a perfect result on the wall. Sheen level changes how white reads — a matt emulsion and a gloss trim in the *same* colour will look different because of how they bounce light. So if you're matching Chantilly Lace trim, match the finish too, not just the colour. And as ever, get a tester pot and look at it in your own light across a full day before you commit a single full tin — north light and afternoon sun will tell you different stories.
For my money, White Cotton is the straight swap. Reach for DH White if you want the upgraded Heritage finish and don't mind the marginally lower LRV.