diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -389,8 +389,9 @@
     'rsrc/js/application/diffusion/behavior-pull-lastmodified.js' => 'c715c123',
     'rsrc/js/application/doorkeeper/behavior-doorkeeper-tag.js' => '6a85bc5a',
     'rsrc/js/application/drydock/drydock-live-operation-status.js' => '47a0728b',
-    'rsrc/js/application/fact/Chart.js' => 'b88a227d',
-    'rsrc/js/application/fact/ChartCurtainView.js' => 'd10a3c25',
+    'rsrc/js/application/fact/Chart.js' => 'eec96de0',
+    'rsrc/js/application/fact/ChartCurtainView.js' => '86954222',
+    'rsrc/js/application/fact/ChartFunctionLabel.js' => '81de1dab',
     'rsrc/js/application/files/behavior-document-engine.js' => '243d6c22',
     'rsrc/js/application/files/behavior-icon-composer.js' => '38a6cedb',
     'rsrc/js/application/files/behavior-launch-icon-composer.js' => 'a17b84f1',
@@ -697,8 +698,9 @@
     'javelin-behavior-user-menu' => '60cd9241',
     'javelin-behavior-view-placeholder' => 'a9942052',
     'javelin-behavior-workflow' => '9623adc1',
-    'javelin-chart' => 'b88a227d',
-    'javelin-chart-curtain-view' => 'd10a3c25',
+    'javelin-chart' => 'eec96de0',
+    'javelin-chart-curtain-view' => '86954222',
+    'javelin-chart-function-label' => '81de1dab',
     'javelin-color' => '78f811c9',
     'javelin-cookie' => '05d290ef',
     'javelin-diffusion-locate-file-source' => '94243d89',
@@ -1933,11 +1935,6 @@
       'javelin-dom',
       'phabricator-draggable-list',
     ),
-    'b88a227d' => array(
-      'phui-chart-css',
-      'd3',
-      'javelin-chart-curtain-view',
-    ),
     'b9109f8f' => array(
       'javelin-behavior',
       'javelin-uri',
@@ -2128,6 +2125,12 @@
       'phabricator-keyboard-shortcut',
       'javelin-stratcom',
     ),
+    'eec96de0' => array(
+      'phui-chart-css',
+      'd3',
+      'javelin-chart-curtain-view',
+      'javelin-chart-function-label',
+    ),
     'ef836bf2' => array(
       'javelin-behavior',
       'javelin-dom',
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2668,6 +2668,7 @@
     'PhabricatorChartFunction' => 'applications/fact/chart/PhabricatorChartFunction.php',
     'PhabricatorChartFunctionArgument' => 'applications/fact/chart/PhabricatorChartFunctionArgument.php',
     'PhabricatorChartFunctionArgumentParser' => 'applications/fact/chart/PhabricatorChartFunctionArgumentParser.php',
+    'PhabricatorChartFunctionLabel' => 'applications/fact/chart/PhabricatorChartFunctionLabel.php',
     'PhabricatorChartRenderingEngine' => 'applications/fact/engine/PhabricatorChartRenderingEngine.php',
     'PhabricatorChartStackedAreaDataset' => 'applications/fact/chart/PhabricatorChartStackedAreaDataset.php',
     'PhabricatorChatLogApplication' => 'applications/chatlog/application/PhabricatorChatLogApplication.php',
@@ -8683,6 +8684,7 @@
     'PhabricatorChartFunction' => 'Phobject',
     'PhabricatorChartFunctionArgument' => 'Phobject',
     'PhabricatorChartFunctionArgumentParser' => 'Phobject',
+    'PhabricatorChartFunctionLabel' => 'Phobject',
     'PhabricatorChartRenderingEngine' => 'Phobject',
     'PhabricatorChartStackedAreaDataset' => 'PhabricatorChartDataset',
     'PhabricatorChatLogApplication' => 'PhabricatorApplication',
diff --git a/src/applications/fact/chart/PhabricatorChartFunction.php b/src/applications/fact/chart/PhabricatorChartFunction.php
--- a/src/applications/fact/chart/PhabricatorChartFunction.php
+++ b/src/applications/fact/chart/PhabricatorChartFunction.php
@@ -4,6 +4,7 @@
   extends Phobject {
 
   private $argumentParser;
+  private $functionLabel;
 
   final public function getFunctionKey() {
     return $this->getPhobjectClassConstant('FUNCTIONKEY', 32);
@@ -43,6 +44,22 @@
     return $this;
   }
 
+  public function setFunctionLabel(PhabricatorChartFunctionLabel $label) {
+    $this->functionLabel = $label;
+    return $this;
+  }
+
+  public function getFunctionLabel() {
+    if (!$this->functionLabel) {
+      $this->functionLabel = id(new PhabricatorChartFunctionLabel())
+        ->setName(pht('Unlabeled Function'))
+        ->setColor('rgba(255, 0, 0, 1)')
+        ->setFillColor('rgba(255, 0, 0, 0.15)');
+    }
+
+    return $this->functionLabel;
+  }
+
   final public static function newFromDictionary(array $map) {
     PhutilTypeSpec::checkMap(
       $map,
diff --git a/src/applications/fact/chart/PhabricatorChartFunctionLabel.php b/src/applications/fact/chart/PhabricatorChartFunctionLabel.php
new file mode 100644
--- /dev/null
+++ b/src/applications/fact/chart/PhabricatorChartFunctionLabel.php
@@ -0,0 +1,56 @@
+<?php
+
+final class PhabricatorChartFunctionLabel
+  extends Phobject {
+
+  private $name;
+  private $color;
+  private $icon;
+  private $fillColor;
+
+  public function setName($name) {
+    $this->name = $name;
+    return $this;
+  }
+
+  public function getName() {
+    return $this->name;
+  }
+
+  public function setColor($color) {
+    $this->color = $color;
+    return $this;
+  }
+
+  public function getColor() {
+    return $this->color;
+  }
+
+  public function setIcon($icon) {
+    $this->icon = $icon;
+    return $this;
+  }
+
+  public function getIcon() {
+    return $this->icon;
+  }
+
+  public function setFillColor($fill_color) {
+    $this->fillColor = $fill_color;
+    return $this;
+  }
+
+  public function getFillColor() {
+    return $this->fillColor;
+  }
+
+  public function toWireFormat() {
+    return array(
+      'name' => $this->getName(),
+      'color' => $this->getColor(),
+      'icon' => $this->getIcon(),
+      'fillColor' => $this->getFillColor(),
+    );
+  }
+
+}
diff --git a/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php b/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php
--- a/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php
+++ b/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php
@@ -131,15 +131,20 @@
       $events[] = $event_list;
     }
 
+    $wire_labels = array();
+    foreach ($functions as $function_key => $function) {
+      $label = $function->getFunctionLabel();
+
+      $label->setName(pht('Important Data %s', $function_key));
+
+      $wire_labels[] = $label->toWireFormat();
+    }
+
     $result = array(
       'type' => $this->getDatasetTypeKey(),
       'data' => $series,
       'events' => $events,
-      'color' => array(
-        'blue',
-        'cyan',
-        'green',
-      ),
+      'labels' => $wire_labels,
     );
 
     return $result;
diff --git a/webroot/rsrc/js/application/fact/Chart.js b/webroot/rsrc/js/application/fact/Chart.js
--- a/webroot/rsrc/js/application/fact/Chart.js
+++ b/webroot/rsrc/js/application/fact/Chart.js
@@ -3,6 +3,7 @@
  * @requires phui-chart-css
  *           d3
  *           javelin-chart-curtain-view
+ *           javelin-chart-function-label
  */
 JX.install('Chart', {
 
@@ -144,13 +145,19 @@
         .y(function(d) { return y(d.y1); });
 
       for (var ii = 0; ii < dataset.data.length; ii++) {
+        var label = new JX.ChartFunctionLabel(dataset.labels[ii]);
+
+        var fill_color = label.getFillColor() || label.getColor();
+
         g.append('path')
-          .style('fill', dataset.color[ii % dataset.color.length])
-          .style('opacity', '0.15')
+          .style('fill', fill_color)
           .attr('d', area(dataset.data[ii]));
 
+        var stroke_color = label.getColor();
+
         g.append('path')
           .attr('class', 'line')
+          .style('stroke', stroke_color)
           .attr('d', line(dataset.data[ii]));
 
         g.selectAll('dot')
@@ -181,7 +188,7 @@
             div.style('opacity', 0);
           });
 
-        curtain.addFunctionLabel('Important Data');
+        curtain.addFunctionLabel(label);
       }
     },
 
diff --git a/webroot/rsrc/js/application/fact/ChartCurtainView.js b/webroot/rsrc/js/application/fact/ChartCurtainView.js
--- a/webroot/rsrc/js/application/fact/ChartCurtainView.js
+++ b/webroot/rsrc/js/application/fact/ChartCurtainView.js
@@ -64,17 +64,21 @@
       return this._labelsNode;
     },
 
-    _newFunctionLabelItem: function(item) {
+    _newFunctionLabelItem: function(label) {
       var item_attrs = {
         className: 'chart-function-label-list-item'
       };
 
       var icon = new JX.PHUIXIconView()
-        .setIcon('fa-circle');
+        .setIcon(label.getIcon());
+
+      // Charts may use custom colors, so we can't rely on the CSS classes
+      // which only provide standard colors like "red" and "blue".
+      icon.getNode().style.color = label.getColor();
 
       var content = [
         icon.getNode(),
-        item
+        label.getName()
       ];
 
       return JX.$N('li', item_attrs, content);
diff --git a/webroot/rsrc/js/application/fact/ChartFunctionLabel.js b/webroot/rsrc/js/application/fact/ChartFunctionLabel.js
new file mode 100644
--- /dev/null
+++ b/webroot/rsrc/js/application/fact/ChartFunctionLabel.js
@@ -0,0 +1,35 @@
+/**
+ * @provides javelin-chart-function-label
+ */
+JX.install('ChartFunctionLabel', {
+
+  construct: function(spec) {
+    this._name = spec.name;
+    this._color = spec.color;
+    this._icon = spec.icon;
+    this._fillColor = spec.fillColor;
+  },
+
+  members: {
+    _name: null,
+    _color: null,
+    _icon: null,
+    _fillColor: null,
+
+    getColor: function() {
+      return this._color;
+    },
+
+    getName: function() {
+      return this._name;
+    },
+
+    getIcon: function() {
+      return this._icon || 'fa-circle';
+    },
+
+    getFillColor: function() {
+      return this._fillColor;
+    }
+  }
+});