Terrestrial Titan vs Mechanicus Standard Grey

How close are they?

ΔE 10.7, fair: the same colour family, but not a straight swap. Mechanicus Standard Grey is a little lighter, more muted than Terrestrial Titan.

Can I use Mechanicus Standard Grey instead of Terrestrial Titan?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Mechanicus Standard Grey is a little lighter, more muted than Terrestrial Titan.

Can I use Terrestrial Titan instead of Mechanicus Standard Grey?

The same difference applies the other way round: Terrestrial Titan 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.