Orchid Purple vs Ruby Red

How close are they?

ΔE 28.4, loose: different enough that you should pick on purpose. Ruby Red is a little darker, more saturated, warmer than Orchid Purple.

Can I use Ruby Red instead of Orchid Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 28). Ruby Red is a little darker, more saturated, warmer than Orchid Purple.

Can I use Orchid Purple instead of Ruby Red?

The same difference applies the other way round: Orchid Purple is a little lighter, more muted, 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.