Alteration (with -ch) of Middle High German mol, molle, from Old High German mol, mol(l)o, from Proto-Germanic *mulô, from Proto-Indo-European *molh₂-o- (compare Lithuanian mul̃vas (“yellow, clayey”), Latin mulleus (“ruddy (shoes)”), Sanskrit मल (mála, “dirt”)), from *melh₂- (“dark color”). More at malen.