ΔE 23.8, loose: different enough that you should pick on purpose. Sunset Orange is noticeably lighter, more saturated, warmer than Demon Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Sunset Orange is noticeably lighter, more saturated, warmer than Demon Red.
The same difference applies the other way round: Demon Red is noticeably darker, more muted, 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 Demon Red on the colour wheel See Sunset Orange on the colour wheel
All matches: Demon Red equivalents · Sunset Orange equivalents