ΔE 27.5, loose: different enough that you should pick on purpose. Russet is noticeably darker, more muted, warmer than Pink Horror.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 28). Russet is noticeably darker, more muted, warmer than Pink Horror.
The same difference applies the other way round: Pink Horror is noticeably lighter, more saturated, 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 Pink Horror on the colour wheel See Russet on the colour wheel
All matches: Pink Horror equivalents · Russet equivalents