Fallen Grass vs Light Emerald

How close are they?

ΔE 19.3, loose: different enough that you should pick on purpose. Light Emerald is a little lighter, more saturated, cooler than Fallen Grass.

Can I use Light Emerald instead of Fallen Grass?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Light Emerald is a little lighter, more saturated, cooler than Fallen Grass.

Can I use Fallen Grass instead of Light Emerald?

The same difference applies the other way round: Fallen Grass is a little darker, more muted, warmer.

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.