Moonpetal vs Dusty Rose

How close are they?

ΔE 22.8, loose: different enough that you should pick on purpose. Dusty Rose is a little lighter, much more saturated, warmer than Moonpetal.

Can I use Dusty Rose instead of Moonpetal?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Dusty Rose is a little lighter, much more saturated, warmer than Moonpetal.

Can I use Moonpetal instead of Dusty Rose?

The same difference applies the other way round: Moonpetal is a little darker, much 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.