Dark Turquoise vs Blue Green

How close are they?

ΔE 7.7, close: similar, with a visible difference side by side. Blue Green is a little lighter, warmer than Dark Turquoise.

Can I use Blue Green instead of Dark Turquoise?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Blue Green is a little lighter, warmer than Dark Turquoise.

Can I use Dark Turquoise instead of Blue Green?

The same difference applies the other way round: Dark Turquoise is a little darker, 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.