ΔE 16.8, loose: different enough that you should pick on purpose. Maroon is noticeably darker, more muted, cooler than Ruddy Terra.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Maroon is noticeably darker, more muted, cooler than Ruddy Terra.
The same difference applies the other way round: Ruddy Terra is noticeably lighter, more saturated, 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 Ruddy Terra on the colour wheel See Maroon on the colour wheel
All matches: Ruddy Terra equivalents · Maroon equivalents