ΔE 10.2, fair: the same colour family, but not a straight swap. Ruby Red is a little darker than Ruby Alchemy.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Ruby Red is a little darker than Ruby Alchemy.
The same difference applies the other way round: Ruby Alchemy is a little lighter.
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 Ruby Alchemy on the colour wheel See Ruby Red on the colour wheel
All matches: Ruby Alchemy equivalents · Ruby Red equivalents