How to use enlarged, pixelated textures without texel bleeding

I'm trying to create a game using low-res textures blown up to appear pixelated. Unfortunately, whenever I zoom in on the texture, it appears that the color from one texel has bled into others. n.b. This is not a bilinear filtering issue - I have set the filtering the Point filtering, which makes the image nice and blocky, but still has color bleed issues.

Things I have tried: I have tried changing the texture format (RGB24) to reduce any artifacts from compression. I have disabled mipmaps. I have disabled anisotropic filtering I have toggled the linear parameter in the Texture2D constructor I have set the camera to orthographic I have offset the camera by half-pixel amounts.

Nothing seems to work. I have output the texture directly from unity to a file, and verified that it is texel-perfect, but when viewed inside Unity, the texels bleed.

Raw Texture (enlarged):

Screenshot:

Testing is easy, attach the script to a Plane and point the camera at it (or view it in the scene viewer). It will also output the texture as a png in your project directory.

here is the code:

 using UnityEngine;
 using System.Collections;
 
 public class TextureTest : MonoBehaviour {
 
     private Texture2D texture;
 
     public void Start() {
         int width = 20;
         int height = 20;
         texture = new Texture2D(width, height);
         texture.filterMode = FilterMode.Point;
         for (int row=0; row<height; ++row)    {
             for (int column=0; column<width; ++column)    {
                 Color color = new Color(row % 3 == 0 && column % 3 == 0 ? 1 : 0, 0, 0);
                 texture.SetPixel(column, row, color);
             }
         }
         texture.Apply();
         this.renderer.material.mainTexture = texture;
         
         byte[] bytes = texture.EncodeToPNG();
         System.IO.FileStream stream = new System.IO.FileStream("Texture.png", System.IO.FileMode.Create);
         System.IO.BinaryWriter writer = new System.IO.BinaryWriter(stream);
         writer.Write(bytes);
         writer.Close();
         stream.Close();
         
     }
 }