ΔE 10.1, fair: the same colour family, but not a straight swap. Dawnstone is a little lighter, more muted than IJA #3 Hairanshoku (Grey Indigo).
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Dawnstone is a little lighter, more muted than IJA #3 Hairanshoku (Grey Indigo).
The same difference applies the other way round: IJA #3 Hairanshoku (Grey Indigo) is a little darker, 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 IJA #3 Hairanshoku (Grey Indigo) on the colour wheel See Dawnstone on the colour wheel
All matches: IJA #3 Hairanshoku (Grey Indigo) equivalents · Dawnstone equivalents