ΔE 11.0, fair: the same colour family, but not a straight swap. Royal Purple is a little darker, more saturated than Shyish Purple.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Royal Purple is a little darker, more saturated than Shyish Purple.
The same difference applies the other way round: Shyish Purple is a little lighter, 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.
See Shyish Purple on the colour wheel See Royal Purple on the colour wheel
All matches: Shyish Purple equivalents · Royal Purple equivalents