Zephyr Pink vs Orchid Purple

How close are they?

ΔE 20.6, loose: different enough that you should pick on purpose. Orchid Purple is a little darker, more muted, cooler than Zephyr Pink.

Can I use Orchid Purple instead of Zephyr Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Orchid Purple is a little darker, more muted, cooler than Zephyr Pink.

Can I use Zephyr Pink instead of Orchid Purple?

The same difference applies the other way round: Zephyr Pink is a little lighter, more saturated, 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.