Green Ghost vs Troll Green

How close are they?

ΔE 6.9, close: similar, with a visible difference side by side. Troll Green is cooler than Green Ghost.

Can I use Troll Green instead of Green Ghost?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Troll Green is cooler than Green Ghost.

Can I use Green Ghost instead of Troll Green?

The same difference applies the other way round: Green Ghost is 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.