Spectral Wolf vs Mummy White

How close are they?

ΔE 20.9, loose: different enough that you should pick on purpose. Mummy White is a little darker, much more saturated than Spectral Wolf.

Can I use Mummy White instead of Spectral Wolf?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Mummy White is a little darker, much more saturated than Spectral Wolf.

Can I use Spectral Wolf instead of Mummy White?

The same difference applies the other way round: Spectral Wolf is a little lighter, much 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.