ΔE 17.2, loose: different enough that you should pick on purpose. Gorgon Brown is noticeably lighter, warmer than Maroon.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Gorgon Brown is noticeably lighter, warmer than Maroon.
The same difference applies the other way round: Maroon is noticeably darker, cooler.
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 Maroon on the colour wheel See Gorgon Brown on the colour wheel
All matches: Maroon equivalents · Gorgon Brown equivalents