diff --git a/docs/src/guide/index.md b/docs/src/guide/index.md
index 7b35dd66cc..1469a05c71 100644
--- a/docs/src/guide/index.md
+++ b/docs/src/guide/index.md
@@ -1106,6 +1106,8 @@ property:
 * `stylesheetUrl`: Path and filename, including extension, for the stylesheet to 
 include. This path is relative to the bundle's resources folder (by default,  
 `res`) 
+* `theme`: Optional; if present, this stylesheet will only be included if this
+value matches the `THEME` constant.
  
 To control the order of CSS files, use priority  (see the section on Extension 
 Definitions above.) 
@@ -2323,7 +2325,12 @@ default paths to reach external services are all correct.
 
 ### Configuration Constants
 
+
 The following configuration constants are recognized by Open MCT Web bundles:
+* Common UI elements - `platform/commonUI/general`
+    * `THEME`: A string identifying the current theme symbolically. Individual
+    stylesheets (the `stylesheets` extension category) may specify an optional
+    `theme` property which will be matched against this before inclusion.
 * CouchDB adapter - `platform/persistence/couch`
     * `COUCHDB_PATH`: URL or path to the CouchDB database to be used for domain 
     object persistence. Should not include a trailing slash.
diff --git a/platform/commonUI/general/bundle.json b/platform/commonUI/general/bundle.json
index edaa8ec103..5976b912cc 100644
--- a/platform/commonUI/general/bundle.json
+++ b/platform/commonUI/general/bundle.json
@@ -18,7 +18,7 @@
         "runs": [
             {
                 "implementation": "StyleSheetLoader.js",
-                "depends": [ "stylesheets[]", "$document" ]
+                "depends": [ "stylesheets[]", "$document", "THEME" ]
             }
         ],
         "stylesheets": [
@@ -194,6 +194,11 @@
             {
                 "key": "MCT_SCROLL_Y_ATTRIBUTE",
                 "value": "mctScrollY"
+            },
+            {
+                "key": "THEME",
+                "value": "unspecified",
+                "priority": "fallback"
             }
         ],
         "containers": [
diff --git a/platform/commonUI/general/src/StyleSheetLoader.js b/platform/commonUI/general/src/StyleSheetLoader.js
index 19c0ffc291..9b64303df1 100644
--- a/platform/commonUI/general/src/StyleSheetLoader.js
+++ b/platform/commonUI/general/src/StyleSheetLoader.js
@@ -38,8 +38,9 @@ define(
          * @constructor
          * @param {object[]} stylesheets stylesheet extension definitions
          * @param $document Angular's jqLite-wrapped document element
+         * @param {string} activeTheme the theme in use
          */
-        function StyleSheetLoader(stylesheets, $document) {
+        function StyleSheetLoader(stylesheets, $document, activeTheme) {
             var head = $document.find('head'),
                 document = $document[0];
 
@@ -62,8 +63,15 @@ define(
                 head.append(link);
             }
 
+            // Stylesheets which specify themes should only be applied
+            // when that theme has been declared.
+            function matchesTheme(stylesheet) {
+                return stylesheet.theme === undefined ||
+                    stylesheet.theme === activeTheme;
+            }
+
             // Add all stylesheets from extensions
-            stylesheets.forEach(addStyleSheet);
+            stylesheets.filter(matchesTheme).forEach(addStyleSheet);
         }
 
         return StyleSheetLoader;
diff --git a/platform/commonUI/general/test/StyleSheetLoaderSpec.js b/platform/commonUI/general/test/StyleSheetLoaderSpec.js
index b2c1a7da93..c1db25fb0a 100644
--- a/platform/commonUI/general/test/StyleSheetLoaderSpec.js
+++ b/platform/commonUI/general/test/StyleSheetLoaderSpec.js
@@ -32,10 +32,11 @@ define(
                 mockPlainDocument,
                 mockHead,
                 mockElement,
+                testBundle,
                 loader;
 
             beforeEach(function () {
-                var testBundle = {
+                testBundle = {
                     path: "a/b",
                     resources: "c"
                 };
@@ -72,6 +73,40 @@ define(
                 expect(mockElement.setAttribute)
                     .toHaveBeenCalledWith('href', "a/b/c/d.css");
             });
+
+            describe("for themed stylesheets", function () {
+                var testTheme = "test-theme";
+
+                beforeEach(function () {
+                    testStyleSheets = [{
+                        stylesheetUrl: "themed.css",
+                        bundle: testBundle,
+                        theme: testTheme
+                    }, {
+                        stylesheetUrl: "bad-theme.css",
+                        bundle: testBundle,
+                        theme: 'bad-theme'
+                    }];
+
+                    loader = new StyleSheetLoader(
+                        testStyleSheets,
+                        mockDocument,
+                        testTheme
+                    );
+                });
+
+                it("includes matching themes", function () {
+                    expect(mockElement.setAttribute)
+                        .toHaveBeenCalledWith('href', "a/b/c/themed.css");
+                });
+
+                it("excludes mismatching themes", function () {
+                    expect(mockElement.setAttribute)
+                        .not.toHaveBeenCalledWith('href', "a/b/c/bad-theme.css");
+                });
+            });
+
+
         });
     }
 );
diff --git a/platform/commonUI/themes/espresso/bundle.json b/platform/commonUI/themes/espresso/bundle.json
index 37cab3e412..94c7259027 100644
--- a/platform/commonUI/themes/espresso/bundle.json
+++ b/platform/commonUI/themes/espresso/bundle.json
@@ -1,12 +1,18 @@
 {
-  "name": "Espresso",
-  "description": "Espresso theme: dark and rich",
-  "extensions": {
-    "stylesheets": [
-      {
-        "stylesheetUrl": "css/theme-espresso.css",
-        "priority": 1000
-      }
-    ]
-  }
-}
\ No newline at end of file
+    "name": "Espresso",
+    "description": "Espresso theme: dark and rich",
+    "extensions": {
+        "stylesheets": [
+            {
+                "stylesheetUrl": "css/theme-espresso.css",
+                "priority": 1000
+            }
+        ],
+        "constants": [
+            {
+                "key": "THEME",
+                "value": "espresso"
+            }
+        ]
+    }
+}
diff --git a/platform/commonUI/themes/snow/bundle.json b/platform/commonUI/themes/snow/bundle.json
index 6db1ba21c1..6780df8e33 100644
--- a/platform/commonUI/themes/snow/bundle.json
+++ b/platform/commonUI/themes/snow/bundle.json
@@ -1,12 +1,18 @@
 {
-  "name": "Sonw",
-  "description": "Snow theme: light and cool",
-  "extensions": {
-    "stylesheets": [
-      {
-        "stylesheetUrl": "css/theme-snow.css",
-        "priority": 1000
-      }
-    ]
-  }
-}
\ No newline at end of file
+    "name": "Snow",
+    "description": "Snow theme: light and cool",
+    "extensions": {
+        "stylesheets": [
+            {
+                "stylesheetUrl": "css/theme-snow.css",
+                "priority": 1000
+            }
+        ],
+        "constants": [
+            {
+                "key": "THEME",
+                "value": "snow"
+            }
+        ]
+    }
+}