Field Grey Base #2 (Grey Uniform) vs Dryad Bark

How close are they?

ΔE 9.5, close: similar, with a visible difference side by side. Dryad Bark is a little darker than Field Grey Base #2 (Grey Uniform).

Can I use Dryad Bark instead of Field Grey Base #2 (Grey Uniform)?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Dryad Bark is a little darker than Field Grey Base #2 (Grey Uniform).

Can I use Field Grey Base #2 (Grey Uniform) instead of Dryad Bark?

The same difference applies the other way round: Field Grey Base #2 (Grey Uniform) is a little lighter.

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.