ΔE 11.3, fair: the same colour family, but not a straight swap. Heavy Warm White is a little lighter, cooler than Opal Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Heavy Warm White is a little lighter, cooler than Opal Skin.
The same difference applies the other way round: Opal Skin is a little darker, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Opal Skin on the colour wheel See Heavy Warm White on the colour wheel
All matches: Opal Skin equivalents · Heavy Warm White equivalents