Tree Ancient vs Steel Legion Drab

How close are they?

ΔE 8.4, close: similar, with a visible difference side by side. Steel Legion Drab is a little lighter than Tree Ancient.

Can I use Steel Legion Drab instead of Tree Ancient?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Steel Legion Drab is a little lighter than Tree Ancient.

Can I use Tree Ancient instead of Steel Legion Drab?

The same difference applies the other way round: Tree Ancient is a little darker.

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.