ΔE 21.1, loose: different enough that you should pick on purpose. Frostbite is noticeably lighter, much more muted than Marine Mist.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Frostbite is noticeably lighter, much more muted than Marine Mist.
The same difference applies the other way round: Marine Mist is noticeably darker, 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 Frostbite on the colour wheel
All matches: Marine Mist equivalents · Frostbite equivalents