ΔE 16.1, loose: different enough that you should pick on purpose. N6 Neutral Gray is noticeably lighter than Dawnstone.
Can I use N6 Neutral Gray instead of Dawnstone?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). N6 Neutral Gray is noticeably lighter than Dawnstone.
Can I use Dawnstone instead of N6 Neutral Gray?
The same difference applies the other way round: Dawnstone is noticeably 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.