ΔE 13.7, fair: the same colour family, but not a straight swap. Ishtar Pink is much more muted, warmer than Tourmaline Skin.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Ishtar Pink is much more muted, warmer than Tourmaline Skin.
The same difference applies the other way round: Tourmaline Skin is much more saturated, 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 Tourmaline Skin on the colour wheel See Ishtar Pink on the colour wheel
All matches: Tourmaline Skin equivalents · Ishtar Pink equivalents