ΔE 32.3, loose: different enough that you should pick on purpose. Brown Grey Wash is noticeably lighter, much more muted than Dark Red Tone.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 32). Brown Grey Wash is noticeably lighter, much more muted than Dark Red Tone.
The same difference applies the other way round: Dark Red Tone 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 Dark Red Tone on the colour wheel See Brown Grey Wash on the colour wheel
All matches: Dark Red Tone equivalents · Brown Grey Wash equivalents