Texture2D creating blurry textures

I'm attempting to create a minimap for my tile-based game. There are 160x160 tiles in my game world, and I'd like the walls to be shown as Black on the minimap, and all other areas to be shown as grey. Here is the code that produces my minimap at runtime:

 Texture2D texture = new Texture2D(160, 160);
 texture.filterMode = FilterMode.Point;
 texture.anisoLevel = 1;
 texture.mipMapBias = -0.5f;

 for (int i = 0; i< 160; i++) {
     for (int j = 0; j< 160; j++) {
         if (tileInfo.tilemapWalls.GetTile(i, j, 0) != -1) {
             Color color = Color.black;
             texture.SetPixel(i, j, color);
         }
         else {
             Color color = Color.gray;
             texture.SetPixel(i, j, color);
         }
     }
 }
         
 texture.Apply();
 image.sprite = Sprite.Create(texture,new Rect(0,0,160,160), new Vector2(0,0), 0.1f);

It's fairly simple, and tiles:pixels should be 1:1. The problem is, the texture created appears blurry, as seen in this screenshot:

Sections of wall that aren't very dense appear in varying shades of Grey. Only two colors should be appearing: Grey and Black.

I've tried messing around with filter mode, aniso level, mipmap Bias, and texture size, but this is seemingly the best I can do. Any suggestions for achieving a crisper image?