Sybarite Green vs Fallen Grass

How close are they?

ΔE 22.3, loose: different enough that you should pick on purpose. Fallen Grass is a little darker, much more muted, warmer than Sybarite Green.

Can I use Fallen Grass instead of Sybarite Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Fallen Grass is a little darker, much more muted, warmer than Sybarite Green.

Can I use Sybarite Green instead of Fallen Grass?

The same difference applies the other way round: Sybarite Green is a little lighter, much 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.