The Collaborative International Dictionary of English v.0.48:

Colorado \Col`o*ra"do\, a. [Sp., red.]
   1. Reddish; -- often used in proper names of rivers or
      creeks. [Southwestern U. S.]
      [Webster 1913 Suppl.]

   2. Medium in color and strength; -- said of cigars. [Cant]
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Colorado
    n 1: a state in west central United States in the Rocky
         Mountains [syn: Colorado, Centennial State, CO]
    2: a river in Texas; flows southeast into the Gulf of Mexico
       [syn: Colorado, Colorado River]
    3: an important river in the southwestern United States; rises
       in the Rocky Mountains of northern Colorado and flows
       southwest through Utah into Arizona (where it flows through
       the Grand Canyon) and then southward through the southern tip
       of Nevada, then forming the border between California and
       Arizona and finally into Mexico where it empties into the
       Gulf of California; the main source of water in the
       southwestern United States [syn: Colorado, Colorado
       River]