Mechanicus Standard Grey vs Blue Black

How close are they?

ΔE 11.8, fair: the same colour family, but not a straight swap. Blue Black is noticeably darker, more saturated than Mechanicus Standard Grey.

Can I use Blue Black instead of Mechanicus Standard Grey?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Blue Black is noticeably darker, more saturated than Mechanicus Standard Grey.

Can I use Mechanicus Standard Grey instead of Blue Black?

The same difference applies the other way round: Mechanicus Standard Grey is noticeably lighter, more muted.

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.