Aquamarine vs Cobalt Bluegreen

How close are they?

ΔE 7.0, close: similar, with a visible difference side by side. Cobalt Bluegreen is a little lighter, more muted than Aquamarine.

Can I use Cobalt Bluegreen instead of Aquamarine?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Cobalt Bluegreen is a little lighter, more muted than Aquamarine.

Can I use Aquamarine instead of Cobalt Bluegreen?

The same difference applies the other way round: Aquamarine is a little darker, more saturated.

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.