Grey Teal vs Light Green Blue

How close are they?

ΔE 6.4, close: similar, with a visible difference side by side. Light Green Blue is a little lighter, warmer than Grey Teal.

Can I use Light Green Blue instead of Grey Teal?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Light Green Blue is a little lighter, warmer than Grey Teal.

Can I use Grey Teal instead of Light Green Blue?

The same difference applies the other way round: Grey Teal 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.