ΔE 13.1, fair: the same colour family, but not a straight swap. Dirty Grey is a little lighter, cooler than Arabic Shadow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Dirty Grey is a little lighter, cooler than Arabic Shadow.
The same difference applies the other way round: Arabic Shadow is a little darker, 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 Arabic Shadow on the colour wheel See Dirty Grey on the colour wheel
All matches: Arabic Shadow equivalents · Dirty Grey equivalents