ΔE 36.1, loose: different enough that you should pick on purpose. Radiant Orange is a little darker, much more muted, warmer than Flesh Tearers Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 36). Radiant Orange is a little darker, much more muted, warmer than Flesh Tearers Red.
The same difference applies the other way round: Flesh Tearers Red is a little lighter, much 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 Flesh Tearers Red on the colour wheel See Radiant Orange on the colour wheel
All matches: Flesh Tearers Red equivalents · Radiant Orange equivalents