ΔE 7.1, close: similar, with a visible difference side by side. Dead White is a little lighter than Holy White. They are different kinds of paint: Army Painter Holy White is a one-coat contrast-style paint and Vallejo Dead White is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
✓ Herrick Games paint comparison chart lists these two as equivalents.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dead White is a little lighter than Holy White. They are different kinds of paint.
The same difference applies the other way round: Holy White is a little darker.
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 Holy White on the colour wheel See Dead White on the colour wheel
All matches: Holy White equivalents · Dead White equivalents