Fixed VertexColors support in FBX converter

utils/converters/fbx/convert_to_threejs.py

@@ -860,6 +860,9 @@ def extract_fbx_vertex_colors(mesh):
                 vertexId += 1
             color_indices.append(poly_colors)
 
+        layered_color_indices.append( color_indices )
+        layered_color_values.append( color_values )
+
     color_values = []
     color_indices = []