ΔE 25.6, loose: different enough that you should pick on purpose. Amethyst Rose is a little darker, much more muted, warmer than Rebel Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Amethyst Rose is a little darker, much more muted, warmer than Rebel Red.
The same difference applies the other way round: Rebel 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 Rebel Red on the colour wheel See Amethyst Rose on the colour wheel
All matches: Rebel Red equivalents · Amethyst Rose equivalents