creo4 config.pro option documentation for: INTF2D_OUT_PDF_WHITE_AS_BLACK 
intf2d_out_pdf_white_as_black
yes
*
, no
Controls the export of the user-defined white color (255, 255, 255) of the drawing entities to the PDF format.
yes
- Exports the user-defined white color (255, 255, 255) of the drawing entities as black to the PDF format.
no
- Exports the white color (255, 255, 255) of the drawing entities as is.