diff --git a/package-lock.json b/package-lock.json
index 7ae0cbc..c90af1f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4116,6 +4116,11 @@
       "integrity": "sha1-l4hXRCxEdJ5CBmE+N5RiBYJqvYA=",
       "dev": true
     },
+    "detect-browser": {
+      "version": "4.5.0",
+      "resolved": "https://registry.npmjs.org/detect-browser/-/detect-browser-4.5.0.tgz",
+      "integrity": "sha512-uwyZNBwMhvRIOBIBTuDu+h4/a2bfFE/elUIvAOuKuBZcuy6yAJ/9dOe4r3wyWO/ZW2PcsP0dhEwiVwTPTTJp2Q=="
+    },
     "detect-node": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/detect-node/-/detect-node-2.0.4.tgz",
diff --git a/package.json b/package.json
index e50a873..6fe3fd1 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "classnames": "^2.2.6",
     "codemirror": "^5.40.2",
     "color": "^3.0.0",
+    "detect-browser": "^4.5.0",
     "file-saver": "^1.3.8",
     "jsonlint": "github:josdejong/jsonlint#85a19d7",
     "lodash.capitalize": "^4.2.1",
diff --git a/src/components/App.jsx b/src/components/App.jsx
index 34216c8..b24cb1b 100644
--- a/src/components/App.jsx
+++ b/src/components/App.jsx
@@ -19,6 +19,7 @@ import SourcesModal from './modals/SourcesModal'
 import OpenModal from './modals/OpenModal'
 import ShortcutsModal from './modals/ShortcutsModal'
 import SurveyModal from './modals/SurveyModal'
+import DebugModal from './modals/DebugModal'
 
 import { downloadGlyphsMetadata, downloadSpriteMetadata } from '../libs/metadata'
 import {latest, validate} from '@mapbox/mapbox-gl-style-spec'
@@ -139,6 +140,12 @@ export default class App extends React.Component {
           document.querySelector(".mapboxgl-canvas").focus();
         }
       },
+      {
+        key: "!",
+        handler: () => {
+          this.toggleModal("debug");
+        }
+      },
     ]
 
     document.body.addEventListener("keyup", (e) => {
@@ -203,12 +210,13 @@ export default class App extends React.Component {
         open: false,
         shortcuts: false,
         export: false,
-        survey: localStorage.hasOwnProperty('survey') ? false : true
+        survey: localStorage.hasOwnProperty('survey') ? false : true,
+        debug: false,
       },
-      mapOptions: {
-        showTileBoundaries: queryUtil.asBool(queryObj, "show-tile-boundaries"),
-        showCollisionBoxes: queryUtil.asBool(queryObj, "show-collision-boxes"),
-        showOverdrawInspector: queryUtil.asBool(queryObj, "show-overdraw-inspector")
+      mapboxGlDebugOptions: {
+        showTileBoundaries: false,
+        showCollisionBoxes: false,
+        showOverdrawInspector: false,
       },
     }
 
@@ -217,20 +225,24 @@ export default class App extends React.Component {
     })
   }
 
-  handleKeyPress(e) {
+  handleKeyPress = (e) => {
     if(navigator.platform.toUpperCase().indexOf('MAC') >= 0) {
       if(e.metaKey && e.shiftKey && e.keyCode === 90) {
+        e.preventDefault();
         this.onRedo(e);
       }
       else if(e.metaKey && e.keyCode === 90) {
+        e.preventDefault();
         this.onUndo(e);
       }
     }
     else {
       if(e.ctrlKey && e.keyCode === 90) {
+        e.preventDefault();
         this.onUndo(e);
       }
       else if(e.ctrlKey && e.keyCode === 89) {
+        e.preventDefault();
         this.onRedo(e);
       }
     }
@@ -461,18 +473,22 @@ export default class App extends React.Component {
     }
   }
 
+  _getRenderer () {
+    const metadata = this.state.mapStyle.metadata || {};
+    return metadata['maputnik:renderer'] || 'mbgljs';
+  }
+
   mapRenderer() {
     const mapProps = {
       mapStyle: style.replaceAccessTokens(this.state.mapStyle, {allowFallback: true}),
-      options: this.state.mapOptions,
+      options: this.state.mapboxGlDebugOptions,
       onDataChange: (e) => {
         this.layerWatcher.analyzeMap(e.map)
         this.fetchSources();
       },
     }
 
-    const metadata = this.state.mapStyle.metadata || {}
-    const renderer = metadata['maputnik:renderer'] || 'mbgljs'
+    const renderer = this._getRenderer();
 
     let mapElement;
 
@@ -524,6 +540,15 @@ export default class App extends React.Component {
     this.setModal(modalName, !this.state.isOpen[modalName]);
   }
 
+  onChangeMaboxGlDebug = (key, value) => {
+    this.setState({
+      mapboxGlDebugOptions: {
+        ...this.state.mapboxGlDebugOptions,
+        [key]: value, 
+      }
+    });
+  }
+
   render() {
     const layers = this.state.mapStyle.layers || []
     const selectedLayer = layers.length > 0 ? layers[this.state.selectedLayerIndex] : null
@@ -575,6 +600,13 @@ export default class App extends React.Component {
 
 
     const modals = <div>
+      <DebugModal
+        renderer={this._getRenderer()}
+        mapboxGlDebugOptions={this.state.mapboxGlDebugOptions}
+        onChangeMaboxGlDebug={this.onChangeMaboxGlDebug}
+        isOpen={this.state.isOpen.debug}
+        onOpenToggle={this.toggleModal.bind(this, 'debug')}
+      />
       <ShortcutsModal
         ref={(el) => this.shortcutEl = el}
         isOpen={this.state.isOpen.shortcuts}
diff --git a/src/components/Toolbar.jsx b/src/components/Toolbar.jsx
index e76c984..6f81b86 100644
--- a/src/components/Toolbar.jsx
+++ b/src/components/Toolbar.jsx
@@ -1,6 +1,7 @@
 import React from 'react'
 import PropTypes from 'prop-types'
 import classnames from 'classnames'
+import {detect} from 'detect-browser';
 
 import {MdFileDownload, MdOpenInBrowser, MdSettings, MdLayers, MdHelpOutline, MdFindInPage, MdAssignmentTurnedIn} from 'react-icons/md'
 
@@ -9,6 +10,11 @@ import logoImage from 'maputnik-design/logos/logo-color.svg'
 import pkgJson from '../../package.json'
 
 
+// This is required because of <https://stackoverflow.com/a/49846426>, there isn't another way to detect support that I'm aware of.
+const browser = detect();
+const colorAccessibilityFiltersEnabled = ['chrome', 'firefox'].indexOf(browser.name) > -1;
+
+
 class IconText extends React.Component {
   static propTypes = {
     children: PropTypes.node,
@@ -137,18 +143,22 @@ export default class Toolbar extends React.Component {
       {
         id: "filter-deuteranopia",
         title: "Map (deuteranopia)",
+        disabled: !colorAccessibilityFiltersEnabled,
       },
       {
         id: "filter-protanopia",
         title: "Map (protanopia)",
+        disabled: !colorAccessibilityFiltersEnabled,
       },
       {
         id: "filter-tritanopia",
         title: "Map (tritanopia)",
+        disabled: !colorAccessibilityFiltersEnabled,
       },
       {
         id: "filter-achromatopsia",
         title: "Map (achromatopsia)",
+        disabled: !colorAccessibilityFiltersEnabled,
       },
     ];
 
@@ -201,7 +211,7 @@ export default class Toolbar extends React.Component {
             <select onChange={(e) => this.handleSelection(e.target.value)} value={currentView.id}>
               {views.map((item) => {
                 return (
-                  <option key={item.id} value={item.id}>
+                  <option key={item.id} value={item.id} disabled={item.disabled}>
                     {item.title}
                   </option>
                 );
diff --git a/src/components/inputs/NumberInput.jsx b/src/components/inputs/NumberInput.jsx
index 75ed148..3071e35 100644
--- a/src/components/inputs/NumberInput.jsx
+++ b/src/components/inputs/NumberInput.jsx
@@ -13,25 +13,28 @@ class NumberInput extends React.Component {
   constructor(props) {
     super(props)
     this.state = {
-      value: props.value
+      editing: false,
+      value: props.value,
     }
   }
 
   static getDerivedStateFromProps(props, state) {
-    return {
-      value: props.value
-    };
+    if (!state.editing) {
+      return {
+        value: props.value
+      };
+    }
   }
 
   changeValue(newValue) {
+    this.setState({editing: true});
     const value = parseFloat(newValue)
 
     const hasChanged = this.state.value !== value
     if(this.isValid(value) && hasChanged) {
       this.props.onChange(value)
-    } else {
-      this.setState({ value: newValue })
     }
+    this.setState({ value: newValue })
   }
 
   isValid(v) {
@@ -52,6 +55,7 @@ class NumberInput extends React.Component {
   }
 
   resetValue = () => {
+    this.setState({editing: false});
     // Reset explicitly to default value if value has been cleared
     if(this.state.value === "") {
       return this.changeValue(this.props.default)
diff --git a/src/components/inputs/StringInput.jsx b/src/components/inputs/StringInput.jsx
index f9d2853..875a454 100644
--- a/src/components/inputs/StringInput.jsx
+++ b/src/components/inputs/StringInput.jsx
@@ -14,13 +14,16 @@ class StringInput extends React.Component {
   constructor(props) {
     super(props)
     this.state = {
+      editing: false,
       value: props.value || ''
     }
   }
 
-  componentDidUpdate(prevProps) {
-    if(this.props.value !== prevProps.value) {
-      this.setState({value: this.props.value})
+  static getDerivedStateFromProps(props, state) {
+    if (!state.editing) {
+      return {
+        value: props.value
+      };
     }
   }
 
@@ -51,11 +54,15 @@ class StringInput extends React.Component {
       placeholder: this.props.default,
       onChange: e => {
         this.setState({
+          editing: true,
           value: e.target.value
         })
       },
       onBlur: () => {
-        if(this.state.value!==this.props.value) this.props.onChange(this.state.value)
+        if(this.state.value!==this.props.value) {
+          this.setState({editing: false});
+          this.props.onChange(this.state.value);
+        }
       }
     });
   }
diff --git a/src/components/map/FeatureLayerPopup.jsx b/src/components/map/FeatureLayerPopup.jsx
index 2d0eacb..261c80f 100644
--- a/src/components/map/FeatureLayerPopup.jsx
+++ b/src/components/map/FeatureLayerPopup.jsx
@@ -1,6 +1,7 @@
 import React from 'react'
 import PropTypes from 'prop-types'
 import LayerIcon from '../icons/LayerIcon'
+import {latest, expression, function as styleFunction} from '@mapbox/mapbox-gl-style-spec'
 
 function groupFeaturesBySourceLayer(features) {
   const sources = {}
@@ -28,7 +29,59 @@ function groupFeaturesBySourceLayer(features) {
 class FeatureLayerPopup extends React.Component {
   static propTypes = {
     onLayerSelect: PropTypes.func.isRequired,
-    features: PropTypes.array
+    features: PropTypes.array,
+    zoom: PropTypes.number,
+  }
+
+  _getFeatureColor(feature, zoom) {
+    try {
+      const paintProps = feature.layer.paint;
+      let propName;
+
+      if(paintProps.hasOwnProperty("text-color") && paintProps["text-color"]) {
+        propName = "text-color";
+      }
+      else if (paintProps.hasOwnProperty("fill-color") && paintProps["fill-color"]) {
+        propName = "fill-color";
+      }
+      else if (paintProps.hasOwnProperty("line-color") && paintProps["line-color"]) {
+        propName = "line-color";
+      }
+      else if (paintProps.hasOwnProperty("fill-extrusion-color") && paintProps["fill-extrusion-color"]) {
+        propName = "fill-extrusion-color";
+      }
+
+      if(propName) {
+        const propertySpec = latest["paint_"+feature.layer.type][propName];
+
+        let color = feature.layer.paint[propName];
+
+        if(typeof(color) === "object") {
+          if(color.stops) {
+            color = styleFunction.convertFunction(color, propertySpec);
+          }
+
+          const exprResult = expression.createExpression(color, propertySpec);
+          const val = exprResult.value.evaluate({
+            zoom: zoom
+          }, feature);
+          return val.toString();
+        }
+        else {
+          return color;
+        }
+      }
+      else {
+        // Default color
+        return "black";
+      }
+    }
+    // This is quite complex, just incase there's an edgecase we're missing
+    // always return black if we get an unexpected error.
+    catch (err) {
+      console.error("Unable to get feature color, error:", err);
+      return "black";
+    }
   }
 
   render() {
@@ -36,21 +89,31 @@ class FeatureLayerPopup extends React.Component {
 
     const items = Object.keys(sources).map(vectorLayerId => {
       const layers = sources[vectorLayerId].map((feature, idx) => {
-        return <label
-          key={idx}
-          className="maputnik-popup-layer"
-          onClick={() => {
-            this.props.onLayerSelect(feature.layer.id)
-          }}
+        const featureColor = this._getFeatureColor(feature, this.props.zoom);
+
+        return <div
+            key={idx}
+            className="maputnik-popup-layer"
         >
-          <LayerIcon type={feature.layer.type} style={{
-            width: 14,
-            height: 14,
-            paddingRight: 3
-          }}/>
-          {feature.layer.id}
-          {feature.counter && <span> × {feature.counter}</span>}
-        </label>
+          <div
+            className="maputnik-popup-layer__swatch" 
+            style={{background: featureColor}}
+          ></div>
+          <label
+            className="maputnik-popup-layer__label"
+            onClick={() => {
+              this.props.onLayerSelect(feature.layer.id)
+            }}
+          >
+            <LayerIcon type={feature.layer.type} style={{
+              width: 14,
+              height: 14,
+              paddingRight: 3
+            }}/>
+            {feature.layer.id}
+            {feature.counter && <span> × {feature.counter}</span>}
+          </label>
+        </div>
       })
       return <div key={vectorLayerId}>
         <div className="maputnik-popup-layer-id">{vectorLayerId}</div>
diff --git a/src/components/map/MapboxGlMap.jsx b/src/components/map/MapboxGlMap.jsx
index 5765f84..fb5f523 100644
--- a/src/components/map/MapboxGlMap.jsx
+++ b/src/components/map/MapboxGlMap.jsx
@@ -166,14 +166,18 @@ export default class MapboxGlMap extends React.Component {
         if(this.props.inspectModeEnabled) {
           return renderPopup(<FeaturePropertyPopup features={features} />, tmpNode);
         } else {
-          return renderPopup(<FeatureLayerPopup features={features} onLayerSelect={this.props.onLayerSelect} />, tmpNode);
+          return renderPopup(<FeatureLayerPopup features={features} onLayerSelect={this.props.onLayerSelect} zoom={this.state.zoom} />, tmpNode);
         }
       }
     })
     map.addControl(inspect)
 
     map.on("style.load", () => {
-      this.setState({ map, inspect });
+      this.setState({
+        map,
+        inspect,
+        zoom: map.getZoom()
+      });
       if(this.props.inspectModeEnabled) {
         inspect.toggleInspector();
       }
@@ -185,6 +189,12 @@ export default class MapboxGlMap extends React.Component {
         map: this.state.map
       })
     })
+
+    map.on("zoom", e => {
+      this.setState({
+        zoom: map.getZoom()
+      });
+    })
   }
 
   render() {
diff --git a/src/components/map/OpenLayersMap.jsx b/src/components/map/OpenLayersMap.jsx
index ce77221..9cb5ee2 100644
--- a/src/components/map/OpenLayersMap.jsx
+++ b/src/components/map/OpenLayersMap.jsx
@@ -56,12 +56,8 @@ export default class OpenLayersMap extends React.Component {
     return <div
       ref={x => this.container = x}
       style={{
-        position: "fixed",
-        top: 40,
-        right: 0,
-        bottom: 0,
-        height: 'calc(100% - 40px)',
-        width: "75%",
+        width: "100%",
+        height: "100%",
         backgroundColor: '#fff',
         ...this.props.style,
       }}>
diff --git a/src/components/modals/DebugModal.js b/src/components/modals/DebugModal.js
new file mode 100644
index 0000000..bddb48f
--- /dev/null
+++ b/src/components/modals/DebugModal.js
@@ -0,0 +1,45 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+
+import Modal from './Modal'
+
+
+class DebugModal extends React.Component {
+  static propTypes = {
+    isOpen: PropTypes.bool.isRequired,
+    renderer: PropTypes.string.isRequired,
+    onChangeMaboxGlDebug: PropTypes.func.isRequired,
+    onOpenToggle: PropTypes.func.isRequired,
+    mapboxGlDebugOptions: PropTypes.object,
+  }
+
+  render() {
+    return <Modal
+      data-wd-key="debug-modal"
+      isOpen={this.props.isOpen}
+      onOpenToggle={this.props.onOpenToggle}
+      title={'Debug'}
+    >
+      <div className="maputnik-modal-section maputnik-modal-shortcuts">
+        {this.props.renderer === 'mbgljs' &&
+          <ul>
+            {Object.entries(this.props.mapboxGlDebugOptions).map(([key, val]) => {
+              return <li key={key}>
+                <label>
+                  <input type="checkbox" checked={val} onClick={(e) => this.props.onChangeMaboxGlDebug(key, e.target.checked)} /> {key}
+                </label>
+              </li>
+            })}
+          </ul>
+        }
+        {this.props.renderer === 'ol' &&
+          <div>
+            No debug options available for the OpenLayers renderer
+          </div>
+        }
+      </div>
+    </Modal>
+  }
+}
+
+export default DebugModal;
diff --git a/src/components/modals/ShortcutsModal.jsx b/src/components/modals/ShortcutsModal.jsx
index df8312e..1ec7448 100644
--- a/src/components/modals/ShortcutsModal.jsx
+++ b/src/components/modals/ShortcutsModal.jsx
@@ -40,6 +40,10 @@ class ShortcutsModal extends React.Component {
         key: "m",
         text: "Focus map"
       },
+      {
+        key: "!",
+        text: "Debug modal"
+      },
     ]
 
 
diff --git a/src/styles/_popup.scss b/src/styles/_popup.scss
index 1c6ad92..dc6caf9 100644
--- a/src/styles/_popup.scss
+++ b/src/styles/_popup.scss
@@ -1,4 +1,15 @@
 .maputnik-popup-layer {
+  display: flex;
+  flex-direction: row;
+}
+
+.maputnik-popup-layer__swatch {
+  display: inline-block;
+  width: 5px;
+  align-content: stretch;
+}
+
+.maputnik-popup-layer__label {
   display: block;
   color: $color-lowgray;
   cursor: pointer;