ΔE 12.9, fair: the same colour family, but not a straight swap. Park Green Flat is a little darker, more muted, warmer than Emerald Scream.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Park Green Flat is a little darker, more muted, warmer than Emerald Scream.
The same difference applies the other way round: Emerald Scream is a little lighter, more saturated, 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 Emerald Scream on the colour wheel See Park Green Flat on the colour wheel
All matches: Emerald Scream equivalents · Park Green Flat equivalents