Create a Unity mesh of 2 triangles, in C#

triangles.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class triangles : MonoBehaviour {

  void Start ()
    {
    gameObject.AddComponent<MeshFilter>();
    gameObject.AddComponent<MeshRenderer>();
    Material mat = new Material(Shader.Find("Custom/Vertex Colored"));
    GetComponent<Renderer>().material = mat;
    Vector3 p0 = new Vector3(-2f,0f,-1f);
    Vector3 p1 = new Vector3(0f,1f,-1f);
    Vector3 p2 = new Vector3(1f,0f,-1f);
    Vector3 p3 = new Vector3(0f,-1f,-1f);
    Vector3[] newVertices = new Vector3[4];
    newVertices[0] = p0;
    newVertices[1] = p1;
    newVertices[2] = p2;
    newVertices[3] = p3;
    Color[] newColors = new Color[4];
    newColors[0] = new Color(1, 0, 0);
    newColors[1] = new Color(0, 1, 0);
    newColors[2] = new Color(0, 0, 1);
    newColors[3] = new Color(1, 1, 0);
    int[] newTriangles = new int[6];
    newTriangles[0] = 0;
    newTriangles[1] = 1;
    newTriangles[2] = 2;
    newTriangles[3] = 0;
    newTriangles[4] = 2;
    newTriangles[5] = 3;
    Mesh m = GetComponent<MeshFilter>().mesh;
    m.vertices = newVertices;
    m.colors = newColors;
    m.triangles = newTriangles;
    }
    
  void Update ()
    {
    }
}