ΔE 19.0, loose: different enough that you should pick on purpose. Bright Neutral Grey is a little darker, much more muted than Marine Mist.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Bright Neutral Grey is a little darker, much more muted than Marine Mist.
The same difference applies the other way round: Marine Mist 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.
See Marine Mist on the colour wheel See Bright Neutral Grey on the colour wheel
All matches: Marine Mist equivalents · Bright Neutral Grey equivalents