Morning Sky vs Blue Green

How close are they?

ΔE 7.1, close: similar, with a visible difference side by side. Blue Green is a little darker, cooler than Morning Sky.

Can I use Blue Green instead of Morning Sky?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Blue Green is a little darker, cooler than Morning Sky.

Can I use Morning Sky instead of Blue Green?

The same difference applies the other way round: Morning Sky is a little lighter, 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.