Dark Boot Brown vs Dataslate Grey

How close are they?

ΔE 6.7, close: similar, with a visible difference side by side. Dataslate Grey is more muted than Dark Boot Brown.

Can I use Dataslate Grey instead of Dark Boot Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dataslate Grey is more muted than Dark Boot Brown.

Can I use Dark Boot Brown instead of Dataslate Grey?

The same difference applies the other way round: Dark Boot Brown is 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.