ΔE 10.2, fair: the same colour family, but not a straight swap. Sail Color is more saturated, cooler than IDF Gray 1 (-1981 Sinai).
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Sail Color is more saturated, cooler than IDF Gray 1 (-1981 Sinai).
The same difference applies the other way round: IDF Gray 1 (-1981 Sinai) is more muted, 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 IDF Gray 1 (-1981 Sinai) on the colour wheel See Sail Color on the colour wheel
All matches: IDF Gray 1 (-1981 Sinai) equivalents · Sail Color equivalents