ΔE 10.1, fair: the same colour family, but not a straight swap. Ruby Skin is a little lighter, more saturated than Basic Skin Tone.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Ruby Skin is a little lighter, more saturated than Basic Skin Tone.
The same difference applies the other way round: Basic Skin Tone is a little darker, more muted.
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 Basic Skin Tone on the colour wheel See Ruby Skin on the colour wheel
All matches: Basic Skin Tone equivalents · Ruby Skin equivalents