ΔE 18.5, loose: different enough that you should pick on purpose. Impish Rouge is a little lighter, warmer than Orchid.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Impish Rouge is a little lighter, warmer than Orchid.
The same difference applies the other way round: Orchid is a little darker, cooler.
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 Orchid on the colour wheel See Impish Rouge on the colour wheel
All matches: Orchid equivalents · Impish Rouge equivalents