ΔE 10.3, fair: the same colour family, but not a straight swap. Character Red is more saturated than Astorath Red.
Can I use Character Red instead of Astorath Red?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Character Red is more saturated than Astorath Red.
Can I use Astorath Red instead of Character Red?
The same difference applies the other way round: Astorath Red is more muted.
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.