Warboss Green vs Shadowed Green

How close are they?

ΔE 8.8, close: similar, with a visible difference side by side. Shadowed Green is a little darker than Warboss Green.

Can I use Shadowed Green instead of Warboss Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Shadowed Green is a little darker than Warboss Green.

Can I use Warboss Green instead of Shadowed Green?

The same difference applies the other way round: Warboss Green is a little lighter.

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.