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