This happens to me. I have attempted to plot to PDF with 4 different drivers (Adobe, Autodesk, Scan Soft and Docucom). Using Civil 3d 2011 x64 on W7x64(i7-2600@3.4GHz, 8GB ram). I have had a couple of pdf plots that seemed to work until closer examination showed either vector or raster lines in a darker shade in the filled areas. It has been suggested that the transparency is a problem (known bug since 2010). I've enabled and disabled transparency in the plotter setup with odd results - it only plotted an 8.5x11 corner of a plot that is 36x48. Exporting to dwfx then to PDF does not work either. Also tested changing the Raster and Vector setting with no difference. When none of the plot options (page setup) are set, the colors do not match the dwg. Anybody have anything else to try?
![Autodesk Design & Make Report](https://forums.autodesk.com/t5/image/serverpage/image-id/1350519iCB55845EBFC43016/image-size/large?v=v2&px=999" "Autodesk Design & Make Report")