Muher

dama - brown, reddish (EDG 207)

Phonologically and semantically compatible with the present root, but Leslau considers it to be Cushitism.

PS
*dhm - to be dark (Fronzaroli 1965a: 138–139, 145, 149; Kogan 2011: 196; EDA II)

One cannot exclude that Hbr. nidhām “astounded, confused” (HALOT 214) belongs to this root with a metaphoric shift of meaning (< “dark, gloomy”, сf. Russian мрачный). Admittedly, the context of the only passage where it is attested (Jr 14:9) rather suggests the meaning “helpless”.