Royal Purple vs Orchid Purple

How close are they?

ΔE 26.4, loose: different enough that you should pick on purpose. Orchid Purple is noticeably lighter, much more muted, warmer than Royal Purple.

Can I use Orchid Purple instead of Royal Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Orchid Purple is noticeably lighter, much more muted, warmer than Royal Purple.

Can I use Royal Purple instead of Orchid Purple?

The same difference applies the other way round: Royal Purple is noticeably darker, much more saturated, 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.