ΔE 23.4, loose: different enough that you should pick on purpose. Royal Purple is noticeably darker, more saturated, cooler than Royal Cloak.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Royal Purple is noticeably darker, more saturated, cooler than Royal Cloak.
The same difference applies the other way round: Royal Cloak is noticeably lighter, more muted, warmer.
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 Royal Cloak on the colour wheel See Royal Purple on the colour wheel
All matches: Royal Cloak equivalents · Royal Purple equivalents