Dusty Rose vs Faded Red

How close are they?

ΔE 18.6, loose: different enough that you should pick on purpose. Faded Red is noticeably darker, much more muted than Dusty Rose.

Can I use Faded Red instead of Dusty Rose?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Faded Red is noticeably darker, much more muted than Dusty Rose.

Can I use Dusty Rose instead of Faded Red?

The same difference applies the other way round: Dusty Rose is noticeably lighter, much more saturated.

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.