Pastel Pink vs Pink

How close are they?

ΔE 27.5, loose: different enough that you should pick on purpose. Pink is noticeably darker, much more muted than Pastel Pink.

Can I use Pink instead of Pastel Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 28). Pink is noticeably darker, much more muted than Pastel Pink.

Can I use Pastel Pink instead of Pink?

The same difference applies the other way round: Pastel Pink 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.