Vertex color not visible outside of unity

hey i am trying to color my mesh using vertex color which is working perfectly fine using particle shader. but the issue is i need to export the mesh into .fbx format in runtime. and for that i am using FBXExporter which is in unity registry. when i export the mesh from editor i can export it as binary .fbx, therefore i am able to import it in blender and see it from vertex paint to see my vertex color.
But,
when i am to export it in runtime i am only able to export in ascii .fbx which i cannot import in blender and also no vertex color is shown in 3d viewer software.
thank you in advance.

using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Serialization;
using UnityEditor.Formats.Fbx.Exporter;
using UnityEngine;

public class ExportingMeshToFBX : MonoBehaviour
{
public void ExportGameObjects()
{
        GameObject[] objects = new GameObject[1];
        objects[0]=GetComponent<MeshStuff>().newmesh;
    ExportOptions options = new ExportOptions();
    string filePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) + "\\Documents", "FBXObject.fbx");
    ModelExporter.ExportObjects(filePath, objects);
}

}

I just want to view my vertex color outside of unity which is in ascii .fbx format
(anywhere is fine 3d viewer, paint 3d or even blender itself)