ΔE 12.8, fair: the same colour family, but not a straight swap. Wraithbone is a little darker, warmer than Green-Grey.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Wraithbone is a little darker, warmer than Green-Grey.
The same difference applies the other way round: Green-Grey is a little lighter, 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 Green-Grey on the colour wheel See Wraithbone on the colour wheel
All matches: Green-Grey equivalents · Wraithbone equivalents