diff --git a/Changelog.md b/Changelog.md
index 60f4b4d..e275b31 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,8 @@
 # Changelog
 
+# v0.10
+ - Change heatmap into a voronoi diagram ([#30](https://github.com/ConnectedHumber/Air-Quality-Web/issues/30))
+
 # v0.9.2 - 3rd June 2019
  - [API] Updated the [API documentation](https://aq.connectedhumber.org/__nightdocs/05-API-Docs.html) with a quick reference of the available actions at the top.
 
diff --git a/client_src/js/Overlay/VoronoiManager.mjs b/client_src/js/Overlay/VoronoiManager.mjs
index b61ed57..26fd472 100644
--- a/client_src/js/Overlay/VoronoiManager.mjs
+++ b/client_src/js/Overlay/VoronoiManager.mjs
@@ -14,24 +14,20 @@ import Vector2 from '../Helpers/Vector2.mjs';
 import GetFromUrl from '../Helpers/GetFromUrl.mjs';
 
 class VoronoiManager {
-	get layer() { return this.overlay.layer; }
 	
-	constructor(in_device_data, map) {
+	constructor(in_device_data, in_map) {
 		this.device_data = in_device_data;
+		this.map = in_map;
+		
+		this.layer = null;
 		
-		this.setup_overlay(map);
 		this.setup_guage();
+		this.setup_overlay();
 	}
 	
-	setup_overlay(map) {
+	setup_overlay() {
 		this.overlay = new VoronoiOverlay();
-		this.overlay.addCells(...this.device_data.devices
-			.filter((device) => typeof device.latitude == "number" &&
-				typeof device.longitude == "number")
-			.map((device) => 
-				new VoronoiCell(new Vector2(device.longitude, device.latitude))
-			));
-		this.overlay.add_to(map);
+		this.set_data(new Date(), "PM25"); // TODO: Make this customisable
 	}
 	
 	setup_guage() {
@@ -60,11 +56,19 @@ class VoronoiManager {
 					device.longitude,
 					device.latitude
 				),
+				// See https://gka.github.io/chroma.js/
 				this.spec.chroma(row.value).toString()
 			));
-			
 		}
 		
+		this.overlay.set_cells(result);
+		
+		if(this.layer !== null)
+			this.layer.remove(); // Remove the old layer if it exists
+		// Generate & add the new layer
+		this.layer = this.overlay.generate_layer();
+		this.layer.addTo(this.map);
+		
 		console.log(result);
 	}
 }
diff --git a/client_src/js/Overlay/VoronoiOverlay.mjs b/client_src/js/Overlay/VoronoiOverlay.mjs
index 77bd94c..7356ab0 100644
--- a/client_src/js/Overlay/VoronoiOverlay.mjs
+++ b/client_src/js/Overlay/VoronoiOverlay.mjs
@@ -20,15 +20,15 @@ class VoronoiOverlay {
 	 * Sets the list of cells in the voronoi overlay.
 	 * @param {VoronoiCell[]} cells The cells to add, as an array.
 	 */
-	setCells(cells) {
+	set_cells(cells) {
 		this.cells.length = 0;
-		this.addCells(...cells);
+		this.add_cells(...cells);
 	}
 	/**
 	 * Adds a cell to the voronoi overlay.
 	 * @param {VoronoiCell} cells The cell to add. May be specified as many times as requires to add cells in bulk.
 	 */
-	addCells(...cells) {
+	add_cells(...cells) {
 		this.cells.push(...cells);
 	}
 	
@@ -99,23 +99,21 @@ class VoronoiOverlay {
 					"coordinates": [cell.polygon.map((point) => [point.x, point.y])],
 				},
 				"properties": {
-					// TODO: Replace this with an actual colour
-					"colour": `hsl(${(Math.random()*360).toFixed(2)}, 50%, 50%)`
+					"colour": cell.colour == null ? "hsl(0, 100%, 100%)" : cell.colour
 				}
 			});
 		}
 		return geojson;
 	}
 	
-	add_to(map) {
-		this.layer = L.geoJSON(this.render(), {
-			style: (feature) => { return { color: feature.properties.colour } }
+	generate_layer() {
+		return L.geoJSON(this.render(), {
+			// FUTURE: If we want to be even moar fanceh, we can check out https://leafletjs.com/reference-1.5.0.html#path
+			style: (feature) => { return {
+				color: feature.properties.colour,
+				fillOpacity: 0.4
+			} }
 		});
-		this.layer.addTo(map);
-	}
-	
-	generate_overlay() {
-		// TODO: Generate the Leaflet SVGOverlay here
 	}
 }
 
diff --git a/package-lock.json b/package-lock.json
index 396fee4..fe973d1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -30,6 +30,12 @@
       "integrity": "sha512-z4j5PWjQff3qGF+5nJIegI5b7drtGA6+XAxoAOINZYkkUuwlmBvjbGtruUAugbaxQkLcCklKZ88dZaPSnFNggg==",
       "dev": true
     },
+    "@types/chroma-js": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/@types/chroma-js/-/chroma-js-1.4.1.tgz",
+      "integrity": "sha512-i9hUiO3bwgmzZUDwBuR65WqsBQ/nwN+H2fKX0bykXCdd8cFQEuIj8vI7FXjyb2f5z5h+pv76I/uakikKSgaqTA==",
+      "dev": true
+    },
     "@types/d3-delaunay": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/@types/d3-delaunay/-/d3-delaunay-4.1.0.tgz",
diff --git a/package.json b/package.json
index f219cd7..b7bd817 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
 	},
 	"devDependencies": {
 		"@types/chart.js": "^2.7.53",
+		"@types/chroma-js": "^1.4.1",
 		"@types/d3-delaunay": "^4.1.0",
 		"@types/leaflet": "^1.4.4",
 		"@types/leaflet-fullscreen": "^1.0.4",