Pale Green vs Angel Green

How close are they?

ΔE 18.9, loose: different enough that you should pick on purpose. Angel Green is noticeably darker, more saturated, warmer than Pale Green.

Can I use Angel Green instead of Pale Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Angel Green is noticeably darker, more saturated, warmer than Pale Green.

Can I use Pale Green instead of Angel Green?

The same difference applies the other way round: Pale Green is noticeably 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.