sienna : Idioms & Phrases

• noun a shade of brown with a tinge of red
  Venetian red; mahogany; sepia; reddish brown.
  
• noun a reddish-brown pigment produced by roasting sienna
  

WordNet

• sienna made of a much redder color by the action of fire.

Webster 1913

• noun a medium to dark tan color
  yellowish brown; caramel brown; caramel; buff.
  
• noun a yellowish-brown pigment made from untreated sienna
  

WordNet

• sienna in its natural state, of a transparent yellowish brown color.

Webster 1913