Wordnet 3.0
NOUN (1)
1. 
 a sturdy twilled cloth of a yellowish brown color used especially for military uniforms; 
ADJECTIVE (1)
1. 
 of a yellowish brown color; 
The Collaborative International Dictionary of English v.0.48:
Khaki \Kha"ki\ (k[aum]"k[-e]), a. [Hind. kh[=a]k[imac], lit.,
   dusty, dust-colored, fr. Per. kh[=a]k dust.]
   Of a dull brownish yellow, or drab color; -- applied to
   cloth, originally to a stout brownish cotton cloth, used in
   making uniforms in the Anglo-Indian army.
   Note: In the United States service the summer uniform of
         cotton is officially designated khaki; the winter
         uniform of wool, olive drab.
         [Webster 1913 Suppl.]
The Collaborative International Dictionary of English v.0.48:
Khaki \Kha"ki\, n.
   Any kind of khaki cloth; hence, a uniform of khaki or,
   rarely, a soldier clad in khaki. In the United States and
   British armies khaki or cloth of a very similar color is
   almost exclusively used for service in the field.
   [Webster 1913 Suppl.]
The Collaborative International Dictionary of English v.0.48:
colorful \colorful\ adj.
   1. having striking color. Opposite of colorless.
   Note: [Narrower terms: changeable, chatoyant, iridescent,
         shot; deep, rich; flaming; fluorescent, glowing;
         prismatic; psychedelic; red, ruddy, flushed,
         empurpled]
   Syn: colourful.
        [WordNet 1.5]
   2. striking in variety and interest. Opposite of colorless
      or dull. [Narrower terms: brave, fine, gay, glorious;
      flamboyant, resplendent, unrestrained; flashy, gaudy,
      jazzy, showy, snazzy, sporty; picturesque]
      [WordNet 1.5]
   3. having color or a certain color; not black, white or grey;
      as, colored crepe paper. Opposite of colorless and
      monochrome.
   Note: [Narrower terms: tinted; touched, tinged; amber,
         brownish-yellow, yellow-brown; amethyst; auburn,
         reddish-brown; aureate, gilded, gilt, gold, golden;
         azure, cerulean, sky-blue, bright blue; bicolor,
         bicolour, bicolored, bicoloured, bichrome; blue,
         bluish, light-blue, dark-blue; blushful,
         blush-colored, rosy; bottle-green; bronze, bronzy;
         brown, brownish, dark-brown; buff; canary,
         canary-yellow; caramel, caramel brown; carnation;
         chartreuse; chestnut; dun; earth-colored,
         earthlike; fuscous; green, greenish, light-green,
         dark-green; jade, jade-green; khaki; lavender,
         lilac; mauve; moss green, mosstone; motley,
         multicolor, culticolour, multicolored, multicoloured,
         painted, particolored, particoloured, piebald, pied,
         varicolored, varicoloured; mousy, mouse-colored;
         ocher, ochre; olive-brown; olive-drab; olive;
         orange, orangish; peacock-blue; pink, pinkish;
         purple, violet, purplish; red, blood-red, carmine,
         cerise, cherry, cherry-red, crimson, ruby, ruby-red,
         scarlet; red, reddish; rose, roseate; rose-red;
         rust, rusty, rust-colored; snuff, snuff-brown,
         snuff-color, snuff-colour, snuff-colored,
         snuff-coloured, mummy-brown, chukker-brown; sorrel,
         brownish-orange; stone, stone-gray; straw-color,
         straw-colored, straw-coloured; tan; tangerine;
         tawny; ultramarine; umber; vermilion,
         vermillion, cinibar, Chinese-red; yellow, yellowish;
         yellow-green; avocado; bay; beige; blae
         bluish-black or gray-blue); coral; creamy; cress
         green, cresson, watercress; hazel; honey,
         honey-colored; hued(postnominal); magenta;
         maroon; pea-green; russet; sage, sage-green;
         sea-green] [Also See: chromatic, colored, dark,
         light.]
   Syn: colored, coloured, in color(predicate).
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
khaki
    adj 1: of a yellowish brown color
    n 1: a sturdy twilled cloth of a yellowish brown color used
         especially for military uniforms
Moby Thesaurus II by Grady Ward, 1.0:
40 Moby Thesaurus words for "khaki":
   beige, brown, brownish, brownish-yellow, brunet, chocolate,
   cinnamon, cocoa, cocoa-brown, coffee, coffee-brown, drab, dun,
   dun-brown, dun-drab, ecru, fawn, fawn-colored, fuscous, grege,
   hazel, lurid, nut-brown, olive-brown, olive-drab, seal, seal-brown,
   sepia, snuff-colored, sorrel, tan, taupe, tawny, toast,
   toast-brown, umber, umber-colored, walnut, walnut-brown,
   yellowish-brown