The Collaborative International Dictionary of English v.0.48:

Nut-brown \Nut"-brown`\, a.
   Brown as a nut long kept and dried. "The spicy nutbrown ale."
   --Milton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

brunet \bru*net"\, Brunette \Bru*nette"\, adj.
   1. being or having dark-colored skin and hair; contrasted
      with blond. [Narrower terms: adust, sunburned burned
      brown by the sun; black, brown; black-haired,
      dark-haired; browned, suntanned, tanned; grizzled,
      roan; nutbrown]
      [WordNet 1.5] brunet

WordNet (r) 3.0 (2006):

nutbrown
    adj 1: of the color of nuts; "nutbrown hair"