make USE_CATEGORIES optional

src/components/Layout.js

@@ -16,6 +16,7 @@ import Notification from './Notification.jsx'
 import StaticPage from './StaticPage'
 import TemplateCover from './TemplateCover'
 
+import colors from '../common/global'
 import { binarySearch } from '../common/utilities'
 import { isMobile } from 'react-device-detect'
 
@@ -87,6 +88,8 @@ class Dashboard extends React.Component {
   }
 
   getCategoryColor (category) {
+    if (!this.props.features.USE_CATEGORIES) { return colors.fallbackEventColor }
+
     const cat = this.props.ui.style.categories[category]
     if (cat) {
       return cat
@@ -168,7 +171,7 @@ class Dashboard extends React.Component {
           methods={{
             onSelect: ev => this.handleSelect(ev, 0),
             onUpdateTimerange: actions.updateTimeRange,
-            getCategoryColor: category => this.getCategoryColor(category)
+            getCategoryColor: this.getCategoryColor
           }}
         />
         <CardStack
@@ -177,7 +180,7 @@ class Dashboard extends React.Component {
           onHighlight={this.handleHighlight}
           onToggleCardstack={() => actions.updateSelected([])}
           getNarrativeLinks={event => this.getNarrativeLinks(event)}
-          getCategoryColor={category => this.getCategoryColor(category)}
+          getCategoryColor={this.getCategoryColor}
         />
         <NarrativeControls
           narrative={app.narrative ? {