support RGB values that have dimension sizes other than uint16_t
support RGB values that have dimension sizes other than uint16_t

lucadelu/PDAL,Sciumo/PDAL,radiantbluetechnologies/PDAL,DougFirErickson/PDAL,mtCarto/PDAL,lucadelu/PDAL,mtCarto/PDAL,verma/PDAL,jwomeara/PDAL,mpgerlek/PDAL-old,lucadelu/PDAL,verma/PDAL,mpgerlek/PDAL-old,mpgerlek/PDAL-old,lucadelu/PDAL,verma/PDAL,radiantbluetechnologies/PDAL,mtCarto/PDAL,Sciumo/PDAL,mtCarto/PDAL,DougFirErickson/PDAL,Sciumo/PDAL,verma/PDAL,boundlessgeo/PDAL,Sciumo/PDAL,radiantbluetechnologies/PDAL,verma/PDAL,boundlessgeo/PDAL,boundlessgeo/PDAL,verma/PDAL,DougFirErickson/PDAL,DougFirErickson/PDAL,jwomeara/PDAL,boundlessgeo/PDAL,radiantbluetechnologies/PDAL,jwomeara/PDAL,mpgerlek/PDAL-old,jwomeara/PDAL,verma/PDAL