ΔE 14.8, fair: the same colour family, but not a straight swap. Warm Grey is a little darker, more muted, cooler than Ruby Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Warm Grey is a little darker, more muted, cooler than Ruby Skin.
The same difference applies the other way round: Ruby Skin is a little lighter, more saturated, 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 Ruby Skin on the colour wheel See Warm Grey on the colour wheel
All matches: Ruby Skin equivalents · Warm Grey equivalents