Field Green vs Green Sky

How close are they?

ΔE 14.6, fair: the same colour family, but not a straight swap. Green Sky is a little lighter, much more muted than Field Green.

Can I use Green Sky instead of Field Green?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Green Sky is a little lighter, much more muted than Field Green.

Can I use Field Green instead of Green Sky?

The same difference applies the other way round: Field Green is a little darker, 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.