ΔE 10.5, fair: the same colour family, but not a straight swap. Russ. AF Grey Blue is a little darker than Grey Seer.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Russ. AF Grey Blue is a little darker than Grey Seer.
The same difference applies the other way round: Grey Seer is a little lighter.
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 Grey Seer on the colour wheel See Russ. AF Grey Blue on the colour wheel
All matches: Grey Seer equivalents · Russ. AF Grey Blue equivalents