ΔE 12.5, fair: the same colour family, but not a straight swap. Our swatches for the two are almost the same.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). The swatches are almost the same.
The same difference applies the other way round.
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 Base #2 (Grey Uniform) on the colour wheel See Mechanicus Standard Grey on the colour wheel
All matches: Field Grey Base #2 (Grey Uniform) equivalents · Mechanicus Standard Grey equivalents