off-color

from WordNet (r) 3.0 (2006)

off-color
    adj 1: in violation of good taste even verging on the indecent;
           "an indelicate remark"; "an off-color joke" [syn:
           {indelicate}, {off-color}, {off-colour}]
    2: humorously vulgar; "bawdy songs"; "off-color jokes"; "ribald
       language" [syn: {bawdy}, {off-color}, {ribald}]

from The Collaborative International Dictionary of English v.0.48

off-color \off-color\ adj.
   humorously vulgar; mildly obscene; risque; as, an off-color
   joke.

   Syn: bawdy, blue, ribald.
        [WordNet 1.5]