Caliban Green vs Sap Green Hue

How close are they?

ΔE 17.4, loose: different enough that you should pick on purpose. Sap Green Hue is more saturated, warmer than Caliban Green.

Can I use Sap Green Hue instead of Caliban Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Sap Green Hue is more saturated, warmer than Caliban Green.

Can I use Caliban Green instead of Sap Green Hue?

The same difference applies the other way round: Caliban Green is more muted, 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.