ΔE 8.7, close: similar, with a visible difference side by side. Dawnstone is a little lighter, more muted than RAF Dark Slate Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Dawnstone is a little lighter, more muted than RAF Dark Slate Grey.
The same difference applies the other way round: RAF Dark Slate Grey is a little darker, 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.
See RAF Dark Slate Grey on the colour wheel See Dawnstone on the colour wheel
All matches: RAF Dark Slate Grey equivalents · Dawnstone equivalents