ΔE 10.4, fair: the same colour family, but not a straight swap. Royal Purple is a little darker, more muted than Genestealer Purple.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Royal Purple is a little darker, more muted than Genestealer Purple.
The same difference applies the other way round: Genestealer Purple is a little lighter, more saturated.
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 Genestealer Purple on the colour wheel See Royal Purple on the colour wheel
All matches: Genestealer Purple equivalents · Royal Purple equivalents