Dryad Brown vs Slate Grey

How close are they?

ΔE 19.1, loose: different enough that you should pick on purpose. Slate Grey is a little darker, much more muted than Dryad Brown.

Can I use Slate Grey instead of Dryad Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Slate Grey is a little darker, much more muted than Dryad Brown.

Can I use Dryad Brown instead of Slate Grey?

The same difference applies the other way round: Dryad Brown is a little lighter, much 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.