ΔE 14.7, fair: the same colour family, but not a straight swap. Dawnstone is much more muted than Field Grey.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Dawnstone is much more muted than Field Grey.
The same difference applies the other way round: Field Grey is much more saturated.
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 Field Grey on the colour wheel See Dawnstone on the colour wheel
All matches: Field Grey equivalents · Dawnstone equivalents