Apothecary White vs Templar White

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Templar White is a little darker than Apothecary White.

Can I use Templar White instead of Apothecary White?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Templar White is a little darker than Apothecary White.

Can I use Apothecary White instead of Templar White?

The same difference applies the other way round: Apothecary White is a little lighter.

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.