ΔE 22.4, loose: different enough that you should pick on purpose. Magenta is noticeably lighter, much more saturated, cooler than Shadow Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Magenta is noticeably lighter, much more saturated, cooler than Shadow Red.
The same difference applies the other way round: Shadow Red is noticeably darker, much more muted, 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 Shadow Red on the colour wheel See Magenta on the colour wheel
All matches: Shadow Red equivalents · Magenta equivalents