diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/account/DiffPreferences.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/account/DiffPreferences.java
index 5600a24..5c66f3c 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/account/DiffPreferences.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/account/DiffPreferences.java
@@ -15,6 +15,7 @@
 package com.google.gerrit.client.account;
 
 import com.google.gerrit.reviewdb.client.AccountDiffPreference;
+import com.google.gerrit.reviewdb.client.AccountDiffPreference.Theme;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference.Whitespace;
 import com.google.gwt.core.client.JavaScriptObject;
 
@@ -38,6 +39,7 @@
     p.expandAllComments(in.isExpandAllComments());
     p.manualReview(in.isManualReview());
     p.renderEntireFile(in.isRenderEntireFile());
+    p.theme(in.getTheme());
     return p;
   }
 
@@ -56,6 +58,7 @@
     p.setExpandAllComments(expandAllComments());
     p.setManualReview(manualReview());
     p.setRenderEntireFile(renderEntireFile());
+    p.setTheme(theme());
   }
 
   public final void ignoreWhitespace(Whitespace i) {
@@ -63,6 +66,11 @@
   }
   private final native void setIgnoreWhitespaceRaw(String i) /*-{ this.ignore_whitespace = i }-*/;
 
+  public final void theme(Theme i) {
+    setThemeRaw(i != null ? i.toString() : Theme.DEFAULT.toString());
+  }
+  private final native void setThemeRaw(String i) /*-{ this.theme = i }-*/;
+
   public final native void tabSize(int t) /*-{ this.tab_size = t }-*/;
   public final native void lineLength(int c) /*-{ this.line_length = c }-*/;
   public final native void context(int c) /*-{ this.context = c }-*/;
@@ -84,6 +92,12 @@
   }
   private final native String ignoreWhitespaceRaw() /*-{ return this.ignore_whitespace }-*/;
 
+  public final Theme theme() {
+    String s = themeRaw();
+    return s != null ? Theme.valueOf(s) : Theme.DEFAULT;
+  }
+  private final native String themeRaw() /*-{ return this.theme }-*/;
+
   public final int tabSize() {return get("tab_size", 8); }
   public final int context() {return get("context", 10); }
   public final int lineLength() {return get("line_length", 100); }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java
index 6fb0681..b4ac7f2 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java
@@ -29,6 +29,7 @@
 import com.google.gerrit.client.rpc.GerritCallback;
 import com.google.gerrit.client.ui.NpIntTextBox;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference;
+import com.google.gerrit.reviewdb.client.AccountDiffPreference.Theme;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference.Whitespace;
 import com.google.gwt.core.client.GWT;
 import com.google.gwt.event.dom.client.ChangeEvent;
@@ -81,6 +82,7 @@
   @UiField ToggleButton manualReview;
   @UiField ToggleButton expandAllComments;
   @UiField ToggleButton renderEntireFile;
+  @UiField ListBox theme;
   @UiField Button apply;
   @UiField Button save;
 
@@ -89,6 +91,7 @@
 
     initWidget(uiBinder.createAndBindUi(this));
     initIgnoreWhitespace();
+    initTheme();
   }
 
   @Override
@@ -130,6 +133,7 @@
     manualReview.setValue(prefs.manualReview());
     expandAllComments.setValue(prefs.expandAllComments());
     renderEntireFile.setValue(prefs.renderEntireFile());
+    setTheme(prefs.theme());
 
     switch (view.getIntraLineStatus()) {
       case OFF:
@@ -295,6 +299,19 @@
     view.updateRenderEntireFile();
   }
 
+  @UiHandler("theme")
+  void onTheme(ChangeEvent e) {
+    prefs.theme(Theme.valueOf(theme.getValue(theme.getSelectedIndex())));
+    view.operation(new Runnable() {
+      @Override
+      public void run() {
+        String t = prefs.theme().name().toLowerCase();
+        view.getCmFromSide(DisplaySide.A).setOption("theme", t);
+        view.getCmFromSide(DisplaySide.B).setOption("theme", t);
+      }
+    });
+  }
+
   @UiHandler("apply")
   void onApply(ClickEvent e) {
     close();
@@ -355,4 +372,30 @@
         PatchUtil.C.whitespaceIGNORE_ALL_SPACE(),
         IGNORE_ALL_SPACE.name());
   }
+
+  private void setTheme(Theme v) {
+    String name = v != null ? v.name() : Theme.DEFAULT.name();
+    for (int i = 0; i < theme.getItemCount(); i++) {
+      if (theme.getValue(i).equals(name)) {
+        theme.setSelectedIndex(i);
+        return;
+      }
+    }
+    theme.setSelectedIndex(0);
+  }
+
+  private void initTheme() {
+    theme.addItem(
+        Theme.DEFAULT.name().toLowerCase(),
+        Theme.DEFAULT.name());
+    theme.addItem(
+        Theme.ECLIPSE.name().toLowerCase(),
+        Theme.ECLIPSE.name());
+    theme.addItem(
+        Theme.ELEGANT.name().toLowerCase(),
+        Theme.ELEGANT.name());
+    theme.addItem(
+        Theme.NEAT.name().toLowerCase(),
+        Theme.NEAT.name());
+  }
 }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.ui.xml b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.ui.xml
index fd9c5a2..d940590 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.ui.xml
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.ui.xml
@@ -162,6 +162,10 @@
     <hr/>
     <table class='{style.table}'>
       <tr>
+        <th><ui:msg>Theme</ui:msg></th>
+        <td><g:ListBox ui:field='theme'/></td>
+      </tr>
+      <tr>
         <th><ui:msg>Ignore Whitespace</ui:msg></th>
         <td><g:ListBox ui:field='ignoreWhitespace'/></td>
       </tr>
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java
index 1f8c271..b69c57d 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java
@@ -545,6 +545,7 @@
       .set("styleSelectedText", true)
       .set("showTrailingSpace", prefs.showWhitespaceErrors())
       .set("keyMap", "vim_ro")
+      .set("theme", prefs.theme().name().toLowerCase())
       .set("value", meta != null ? contents : "")
       .set("viewportMargin", prefs.renderEntireFile() ? POSITIVE_INFINITY : 10));
   }
diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountDiffPreference.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountDiffPreference.java
index 4c74b5f..7d73574 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountDiffPreference.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountDiffPreference.java
@@ -55,9 +55,17 @@
     }
   }
 
+  public static enum Theme {
+    DEFAULT,
+    ECLIPSE,
+    ELEGANT,
+    NEAT,
+  }
+
   public static AccountDiffPreference createDefault(Account.Id accountId) {
     AccountDiffPreference p = new AccountDiffPreference(accountId);
     p.setIgnoreWhitespace(Whitespace.IGNORE_NONE);
+    p.setTheme(Theme.DEFAULT);
     p.setTabSize(8);
     p.setLineLength(100);
     p.setSyntaxHighlighting(true);
@@ -125,6 +133,9 @@
   @Column(id = 18)
   protected boolean renderEntireFile;
 
+  @Column(id = 19, length = 20, notNull = false)
+  protected String theme;
+
   protected AccountDiffPreference() {
   }
 
@@ -295,4 +306,12 @@
   public void setRenderEntireFile(boolean render) {
     renderEntireFile = render;
   }
+
+  public Theme getTheme() {
+    return theme != null ? Theme.valueOf(theme) : null;
+  }
+
+  public void setTheme(Theme theme) {
+    this.theme = theme != null ? theme.name() : null;
+  }
 }
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/account/GetDiffPreferences.java b/gerrit-server/src/main/java/com/google/gerrit/server/account/GetDiffPreferences.java
index 9418928..ccb0418 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/account/GetDiffPreferences.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/account/GetDiffPreferences.java
@@ -18,6 +18,7 @@
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference;
+import com.google.gerrit.reviewdb.client.AccountDiffPreference.Theme;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference.Whitespace;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
@@ -71,6 +72,7 @@
       info.syntaxHighlighting = p.isSyntaxHighlighting() ? true : null;
       info.tabSize = p.getTabSize();
       info.renderEntireFile = p.isRenderEntireFile() ? true : null;
+      info.theme = p.getTheme();
       return info;
     }
 
@@ -91,5 +93,6 @@
     public Boolean hideLineNumbers;
     public Boolean renderEntireFile;
     public int tabSize;
+    public Theme theme;
   }
 }
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/account/SetDiffPreferences.java b/gerrit-server/src/main/java/com/google/gerrit/server/account/SetDiffPreferences.java
index d773303..146f241 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/account/SetDiffPreferences.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/account/SetDiffPreferences.java
@@ -18,6 +18,7 @@
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference;
+import com.google.gerrit.reviewdb.client.AccountDiffPreference.Theme;
 import com.google.gerrit.reviewdb.client.AccountDiffPreference.Whitespace;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
@@ -48,6 +49,7 @@
     Boolean hideLineNumbers;
     Boolean renderEntireFile;
     Integer tabSize;
+    Theme theme;
   }
 
   private final Provider<CurrentUser> self;
@@ -131,6 +133,9 @@
       if (input.tabSize != null) {
         p.setTabSize(input.tabSize);
       }
+      if (input.theme != null) {
+        p.setTheme(input.theme);
+      }
 
       db.accountDiffPreferences().upsert(Collections.singleton(p));
       db.commit();
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaVersion.java b/gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaVersion.java
index 5cacd92..8800929 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaVersion.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaVersion.java
@@ -32,7 +32,7 @@
 /** A version of the database schema. */
 public abstract class SchemaVersion {
   /** The current schema version. */
-  public static final Class<Schema_92> C = Schema_92.class;
+  public static final Class<Schema_93> C = Schema_93.class;
 
   public static class Module extends AbstractModule {
     @Override
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_93.java b/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_93.java
new file mode 100644
index 0000000..3132aa4
--- /dev/null
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_93.java
@@ -0,0 +1,25 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.schema;
+
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+
+public class Schema_93 extends SchemaVersion {
+  @Inject
+  Schema_93(Provider<Schema_92> prior) {
+    super(prior);
+  }
+}
diff --git a/lib/codemirror/cm3.defs b/lib/codemirror/cm3.defs
index 8de280a..3b8390ccd 100644
--- a/lib/codemirror/cm3.defs
+++ b/lib/codemirror/cm3.defs
@@ -1,6 +1,33 @@
 CM3_CSS = [
   'lib/codemirror.css',
   'addon/dialog/dialog.css',
+  'theme/3024-day.css',
+  'theme/3024-night.css',
+  'theme/ambiance-mobile.css',
+  'theme/ambiance.css',
+  'theme/base16-dark.css',
+  'theme/base16-light.css',
+  'theme/blackboard.css',
+  'theme/cobalt.css',
+  'theme/eclipse.css',
+  'theme/elegant.css',
+  'theme/erlang-dark.css',
+  'theme/lesser-dark.css',
+  'theme/mbo.css',
+  'theme/midnight.css',
+  'theme/monokai.css',
+  'theme/neat.css',
+  'theme/night.css',
+  'theme/paraiso-dark.css',
+  'theme/paraiso-light.css',
+  'theme/rubyblue.css',
+  'theme/solarized.css',
+  'theme/the-matrix.css',
+  'theme/tomorrow-night-eighties.css',
+  'theme/twilight.css',
+  'theme/vibrant-ink.css',
+  'theme/xq-dark.css',
+  'theme/xq-light.css',
 ]
 
 CM3_JS = [