I'm having the same problem as Sarah with writing point clouds to 3D PDF and retaining colour.
I assign the colour from a raster using the PointCloudOnRasterComponentSetter transformer.
Then Coerce to points preserving the colour as an attribute and use this attribute in PDFStyler to assign the colour. Stills comes out black.
Sarah's soloution
"I needed to add an ElevationExtractor, Bufferer and 3D Forcer between the PointCloudCoercer and PDFStyler."
If you're out there Sarah can you explain how you used these transformers to assign the colour from the imagery that is accepted by 3D PDF?
Anyone else with ideas?
Martin