Mummified Grime vs Mummy White

How close are they?

ΔE 20.0, loose: different enough that you should pick on purpose. Mummy White is noticeably lighter, more saturated, warmer than Mummified Grime.

Can I use Mummy White instead of Mummified Grime?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Mummy White is noticeably lighter, more saturated, warmer than Mummified Grime.

Can I use Mummified Grime instead of Mummy White?

The same difference applies the other way round: Mummified Grime is noticeably darker, 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.