Calth Blue Clear vs Eldar Robe

How close are they?

ΔE 8.9, close: similar, with a visible difference side by side. Eldar Robe is more muted, cooler than Calth Blue Clear.

Can I use Eldar Robe instead of Calth Blue Clear?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Eldar Robe is more muted, cooler than Calth Blue Clear.

Can I use Calth Blue Clear instead of Eldar Robe?

The same difference applies the other way round: Calth Blue Clear is more saturated, 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.