Calth Blue Clear vs Exile Blue

How close are they?

ΔE 25.5, loose: different enough that you should pick on purpose. Exile Blue is noticeably darker, much more muted than Calth Blue Clear.

Can I use Exile Blue instead of Calth Blue Clear?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Exile Blue is noticeably darker, much more muted than Calth Blue Clear.

Can I use Calth Blue Clear instead of Exile Blue?

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

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.