ΔE 11.8, fair: the same colour family, but not a straight swap. Rosy Flesh is noticeably lighter, warmer than Celestine Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Rosy Flesh is noticeably lighter, warmer than Celestine Skin.
The same difference applies the other way round: Celestine Skin is noticeably darker, cooler.
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 Celestine Skin on the colour wheel See Rosy Flesh on the colour wheel
All matches: Celestine Skin equivalents · Rosy Flesh equivalents