ΔE 15.2, loose: different enough that you should pick on purpose. Scarlett Red is a little lighter, more saturated, warmer than Astorath Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Scarlett Red is a little lighter, more saturated, warmer than Astorath Red.
The same difference applies the other way round: Astorath Red is a little 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 Astorath Red on the colour wheel See Scarlett Red on the colour wheel
All matches: Astorath Red equivalents · Scarlett Red equivalents