Light Turquoise vs Royal Cloak

How close are they?

ΔE 9.7, close: similar, with a visible difference side by side. Royal Cloak is a little lighter, cooler than Light Turquoise.

Can I use Royal Cloak instead of Light Turquoise?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Royal Cloak is a little lighter, cooler than Light Turquoise.

Can I use Light Turquoise instead of Royal Cloak?

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