Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Color
VP_COMICCOLOR
Parameter: Illumination
VP_COMICILLUMINATION
Parameter: Outline
VP_COMICOUTLINE
Parameter: Edges
VP_COMICEDGES
Parameter: Edge Color
VP_COMICEDGECOLOR
Parameter: Background Color
VP_COMICBACKCOLOR
Parameter: Quantize
VP_COMICQUANTIZE
Parameter: Steps
VP_COMICQUANTIZELEVEL