The raycaster can now pair a floor with a ceiling tile and to demonstrate this I have a blue light that shines on to a stone floor. I also played with just pixelating a regular image rather than painting it and honestly it looks better in a lot of ways.

assets/tiles.json

@@ -3,6 +3,7 @@
     "texture": "assets/floor_tile_test-256.png",
     "collision": false,
     "display": 10398,
+    "ceiling": "ceiling_plain",
     "id": 0
   },
   "wall_plain": {
@@ -23,7 +24,7 @@
     "display": 35,
     "id": 3
   },
-  "plain_ceiling": {
+  "ceiling_plain": {
     "texture": "assets/ceiling_test-256.png",
     "collision": false,
     "display": 35,
@@ -33,6 +34,20 @@
     "texture": "assets/lava_floor-256.png",
     "collision": false,
     "display": 35,
+    "ceiling": "ceiling_plain",
     "id": 5
+  },
+  "large_stone_floor": {
+    "texture": "assets/large_stone_floor-256.png",
+    "collision": false,
+    "display": 35,
+    "ceiling": "ceiling_moss_brick_blue_light",
+    "id": 6
+  },
+  "ceiling_moss_brick_blue_light": {
+    "texture": "assets/ceiling_moss_brick_blue_light-256.png",
+    "collision": false,
+    "display": 35,
+    "id": 7
   }
 }