ΔE 9.3, close: similar, with a visible difference side by side. Ivory Tusk is a little darker, more saturated than Apothecary White. They are different kinds of paint: Citadel Apothecary White is a one-coat contrast-style paint and Two Thin Coats Ivory Tusk is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Ivory Tusk is a little darker, more saturated than Apothecary White. They are different kinds of paint.
The same difference applies the other way round: Apothecary White is a little lighter, more muted.
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.
See Apothecary White on the colour wheel See Ivory Tusk on the colour wheel
All matches: Apothecary White equivalents · Ivory Tusk equivalents