ΔE 16.3, loose: different enough that you should pick on purpose. Nocturnal Red is noticeably lighter, more saturated than Feral Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Nocturnal Red is noticeably lighter, more saturated than Feral Brown.
The same difference applies the other way round: Feral Brown is noticeably darker, more muted.
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 Feral Brown on the colour wheel See Nocturnal Red on the colour wheel
All matches: Feral Brown equivalents · Nocturnal Red equivalents