The styling of Lightspeed layers containing 3D reality meshes constructed with the TLsp3DTileLayerBuilder can be customized by specifying a TLsp3DMeshStyle on the builder. 

ILcdModelDecoder decoder =
    new TLcdCompositeModelDecoder(TLcdServiceLoader.getInstance(ILcdModelDecoder.class));
ILcdModel model = decoder.decode("https://sampleservices.luciad.com/ogc/3dtiles/marseille-mesh/tileset.json");

// Create the mesh style
TLsp3DMeshStyle meshStyle = TLsp3DMeshStyle.newBuilder()
                                           .opacity(0.8f)
                                           .modulationColor(Color.YELLOW)
                                           .build();

// Specify the style on the builder
TLspLayer layer = TLsp3DTileLayerBuilder.newBuilder()
                                        .model(model)
                                        .bodyStyles(TLspPaintState.REGULAR, meshStyle)
                                        .build();