Here’s some disgusting information for you…
Mummy Brown used to be literal.
As in people, in the 1700’s and 1800’s raided Egyptian tombs and took mummified remains… they would then grind up the mummified flesh to make a pasty brown color… fittingly called mummy brown.
To think people used human flesh to make art is astoundingly perverted.
I’m sure some hardcore art-ers would love this since you can present it as some kind of disgusting grand statement.
But anyways, thank the gods mummy browns no longer exist.
Instead any browns you’ll find in painting mediums these days labeled as “mummy” are some standard mineral pigments.