purple wire

( n.)

   [IBM]  Wire  installed  by  Field  Engineers  to work around problems
   discovered  during  testing  or  debugging.  These are called `purple
   wires'  even  when  (as is frequently the case) their actual physical
   color  is  yellow....  Compare  {blue  wire}, {yellow wire}, and {red
   wire}.

[glossary]
[Reference(s) to this entry by made by: {blue wire}{red wire}{yellow wire}]