Faded Green vs Sky Type S

How close are they?

ΔE 9.5, close: similar, with a visible difference side by side. Sky Type S is a little darker, more muted, warmer than Faded Green.

Can I use Sky Type S instead of Faded Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Sky Type S is a little darker, more muted, warmer than Faded Green.

Can I use Faded Green instead of Sky Type S?

The same difference applies the other way round: Faded Green 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.