ΔE 18.6, loose: different enough that you should pick on purpose. Park Green Flat is noticeably darker, more saturated, warmer than Grey Teal.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Park Green Flat is noticeably darker, more saturated, warmer than Grey Teal.
The same difference applies the other way round: Grey Teal 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.
See Grey Teal on the colour wheel See Park Green Flat on the colour wheel
All matches: Grey Teal equivalents · Park Green Flat equivalents