Base Green (Protective) vs Dryad Bark

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Dryad Bark is a little darker, more muted than Base Green (Protective).

Can I use Dryad Bark instead of Base Green (Protective)?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dryad Bark is a little darker, more muted than Base Green (Protective).

Can I use Base Green (Protective) instead of Dryad Bark?

The same difference applies the other way round: Base Green (Protective) is a little lighter, 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.