diff --git a/datamodels/2.x/installation.xml b/datamodels/2.x/installation.xml
index 5f1048422..330736741 100755
--- a/datamodels/2.x/installation.xml
+++ b/datamodels/2.x/installation.xml
@@ -21,7 +21,8 @@
 						<module>combodo-db-tools</module>
 						<module>itop-core-update</module>
 						<module>itop-hub-connector</module>
-						<module>combodo-backoffice-darkmoon-theme</module>
+            <module>combodo-backoffice-darkmoon-theme</module>
+            <module>itop-themes-compat</module>
 					</modules>
 					<mandatory>true</mandatory>
 				</choice>
diff --git a/datamodels/2.x/itop-themes-compat/README.md b/datamodels/2.x/itop-themes-compat/README.md
new file mode 100644
index 000000000..3d0e44fb5
--- /dev/null
+++ b/datamodels/2.x/itop-themes-compat/README.md
@@ -0,0 +1,2 @@
+# Extension Light grey and Test red themes compatibility
+
diff --git a/datamodels/2.x/itop-themes-compat/assets/css/compat.scss b/datamodels/2.x/itop-themes-compat/assets/css/compat.scss
new file mode 100644
index 000000000..e69de29bb
diff --git a/datamodels/2.x/itop-themes-compat/assets/css/css-variables.scss b/datamodels/2.x/itop-themes-compat/assets/css/css-variables.scss
new file mode 100644
index 000000000..e69de29bb
diff --git a/datamodels/2.x/itop-themes-compat/datamodel.itop-themes-compat.xml b/datamodels/2.x/itop-themes-compat/datamodel.itop-themes-compat.xml
new file mode 100644
index 000000000..492c47447
--- /dev/null
+++ b/datamodels/2.x/itop-themes-compat/datamodel.itop-themes-compat.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<itop_design version="3.0">
+  <branding>
+    <themes>
+      <theme id="light-grey" _delta="define">
+        <variables>
+        </variables>
+        <imports>
+          <import id="css-variables">itop-themes-compat/assets/css/css-variables.scss</import>
+        </imports>
+        <stylesheets>
+          <stylesheet id="jqueryui">itop-themes-compat/assets/css/compat.scss</stylesheet>
+          <stylesheet id="main">itop-themes-compat/assets/css/compat.scss</stylesheet>
+          <stylesheet id="fullmoon">../css/backoffice/main.scss</stylesheet>
+        </stylesheets>
+      </theme>
+      <theme id="test-red" _delta="must_exist">
+        <variables>
+          <variable id="backoffice-environment-banner-background-color" _delta="define">#C53030</variable>
+          <variable id="backoffice-environment-banner-text-color" _delta="define">#F7FAFC</variable>
+          <variable id="backoffice-environment-banner-text-content" _delta="define">"THIS IS A TEST INSTANCE"</variable>
+        </variables>
+        <imports>
+          <import id="css-variables" _delta="define">itop-themes-compat/assets/css/css-variables.scss</import>
+        </imports>
+        <stylesheets>
+          <stylesheet id="jqueryui" _delta="define">itop-themes-compat/assets/css/compat.scss</stylesheet>
+          <stylesheet id="main" _delta="define">itop-themes-compat/assets/css/compat.scss</stylesheet>
+        </stylesheets>
+      </theme>
+    </themes>
+  </branding>
+</itop_design>
diff --git a/datamodels/2.x/itop-themes-compat/en.dict.itop-themes-compat.php b/datamodels/2.x/itop-themes-compat/en.dict.itop-themes-compat.php
new file mode 100644
index 000000000..49f12deeb
--- /dev/null
+++ b/datamodels/2.x/itop-themes-compat/en.dict.itop-themes-compat.php
@@ -0,0 +1,11 @@
+<?php
+/**
+ * Localized data
+ *
+ * @copyright   Copyright (C) 2013 XXXXX
+ * @license     http://opensource.org/licenses/AGPL-3.0
+ */
+
+Dict::Add('EN US', 'English', 'English', array(
+	'theme:light-grey' => 'Light Grey (deprecated)',
+));
diff --git a/datamodels/2.x/itop-themes-compat/model.itop-themes-compat.php b/datamodels/2.x/itop-themes-compat/model.itop-themes-compat.php
new file mode 100644
index 000000000..ccc1b539e
--- /dev/null
+++ b/datamodels/2.x/itop-themes-compat/model.itop-themes-compat.php
@@ -0,0 +1,17 @@
+<?php
+
+// PHP Data Model definition file
+
+// WARNING - WARNING - WARNING
+// DO NOT EDIT THIS FILE (unless you know what you are doing)
+//
+// If you provide a datamodel.xxxx.xml file with your module,
+// this file WILL BE overwritten by the compilation of the
+// module (during the setup) if the datamodel.xxxx.xml file
+// contains the definition of new classes or menus.
+//
+// The recommended way to define new classes (for iTop 2.0 and later) is via the XML definition.
+// This file remains in the module's template only for the cases where there is:
+// - either no new class or menu defined in the XML file
+// - or no XML file at all supplied by the module
+
diff --git a/datamodels/2.x/itop-themes-compat/module.itop-themes-compat.php b/datamodels/2.x/itop-themes-compat/module.itop-themes-compat.php
new file mode 100644
index 000000000..d262dc89e
--- /dev/null
+++ b/datamodels/2.x/itop-themes-compat/module.itop-themes-compat.php
@@ -0,0 +1,52 @@
+<?php
+//
+// iTop module definition file
+//
+
+SetupWebPage::AddModule(
+	__FILE__, // Path to the current file, all other file names are relative to the directory containing this file
+	'itop-themes-compat/3.0.1',
+	array(
+		// Identification
+		//
+		'label' => 'Light grey and Test red themes compatibility',
+		'category' => 'business',
+
+		// Setup
+		//
+		'dependencies' => array(
+			'itop-structure/3.0.1',
+		),
+		'mandatory' => false,
+		'visible' => true,
+
+		// Components
+		//
+		'datamodel' => array(
+			'model.itop-themes-compat.php', // Contains the PHP code generated by the "compilation" of datamodel.itop-themes-compat.xml
+		),
+		'webservice' => array(
+			
+		),
+		'data.struct' => array(
+			// add your 'structure' definition XML files here,
+		),
+		'data.sample' => array(
+			// add your sample data XML files here,
+		),
+		
+		// Documentation
+		//
+		'doc.manual_setup' => '', // hyperlink to manual setup documentation, if any
+		'doc.more_information' => '', // hyperlink to more information, if any 
+
+		// Default settings
+		//
+		'settings' => array(
+			// Module specific settings go here, if any
+		),
+	)
+);
+
+
+?>
diff --git a/setup/itopdesignformat.class.inc.php b/setup/itopdesignformat.class.inc.php
index c8f13b536..925b5a090 100644
--- a/setup/itopdesignformat.class.inc.php
+++ b/setup/itopdesignformat.class.inc.php
@@ -667,8 +667,6 @@ class iTopDesignFormat
 	 */
 	protected function From16To15($oFactory)
 	{
-		$oXPath = new DOMXPath($this->oDocument);
-
 		// Remove AttributeTagSet nodes
 		//
 		$sPath = "/itop_design/classes/class/fields/field[@xsi:type='AttributeTagSet']";
@@ -805,15 +803,7 @@ class iTopDesignFormat
 			$oNode->appendChild($oCodeNode);
 		}
 
-		// N°3516 Remove legacy backoffice theme
-		// Remove completely light-grey theme
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="light-grey"]');
-		
 		// Update test-red theme
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="test-red"]/imports/import[@id="css-variables"]');
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="test-red"]/stylesheets/stylesheet[@id="jqueryui"]');
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="test-red"]/stylesheets/stylesheet[@id="main"]');
-
 		$oNodeList = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="backoffice-environment-banner-background-color"]');
 		foreach ($oNodeList as $oNode) {
 			$oNode->setAttribute('id', 'ibo-page-banner--background-color');
@@ -829,21 +819,6 @@ class iTopDesignFormat
 			$oNode->setAttribute('id', 'ibo-page-banner--text-content');
 		}
 
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="test-red"]/stylesheets/stylesheet[@id="environment-banner"]');
-		// Add new stylesheets
-		$oStyleSheetsNode = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/stylesheets')->item(0);
-		if ($oStyleSheetsNode) {
-			$oStyleSheetNode = $oStyleSheetsNode->ownerDocument->createElement("stylesheet");
-			$oStyleSheetNode->setAttribute('id', 'environment-banner');
-			$oStyleSheetNode->appendChild(new DOMText('../css/backoffice/themes/page-banner.scss'));
-			$oStyleSheetsNode->appendChild($oStyleSheetNode);
-
-			$oStyleSheetNode = $oStyleSheetsNode->ownerDocument->createElement("stylesheet");
-			$oStyleSheetNode->setAttribute('id', 'fullmoon');
-			$oStyleSheetNode->appendChild(new DOMText('../css/backoffice/main.scss'));
-			$oStyleSheetsNode->appendChild($oStyleSheetNode);
-		}
-
 		// Add new attribute to theme import nodes
 		$oNodeList = $oXPath->query('/itop_design/branding/themes/theme/imports/import');
 		foreach ($oNodeList as $oNode) {
@@ -923,24 +898,27 @@ class iTopDesignFormat
 		// N°3516 Bring back legacy themes
 		// Update test-red theme
 
-		$oNodeList = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="ibo-page-banner--background-color"]');
-		foreach ($oNodeList as $oNode) {
-			$oNode->setAttribute('id', 'backoffice-environment-banner-background-color');
+		if (!$oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="backoffice-environment-banner-background-color"]')->item(0)) {
+			$oNodeList = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="ibo-page-banner--background-color"]');
+			foreach ($oNodeList as $oNode) {
+				$oNode->setAttribute('id', 'backoffice-environment-banner-background-color');
+			}
 		}
 
-		$oNodeList = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="ibo-page-banner--text-color"]');
-		foreach ($oNodeList as $oNode) {
-			$oNode->setAttribute('id', 'backoffice-environment-banner-text-color');
+		if (!$oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="backoffice-environment-banner-text-color"]')->item(0)) {
+			$oNodeList = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="ibo-page-banner--text-color"]');
+			foreach ($oNodeList as $oNode) {
+				$oNode->setAttribute('id', 'backoffice-environment-banner-text-color');
+			}
 		}
 
-		$oNodeList = $oXPath->query( '/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="ibo-page-banner--text-content"]');
-		foreach ($oNodeList as $oNode) {
-			$oNode->setAttribute('id', 'backoffice-environment-banner-text-content');
+		if (!$oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="backoffice-environment-banner-text-content"]')->item(0)) {
+			$oNodeList = $oXPath->query('/itop_design/branding/themes/theme[@id="test-red"]/variables/variable[@id="ibo-page-banner--text-content"]');
+			foreach ($oNodeList as $oNode) {
+				$oNode->setAttribute('id', 'backoffice-environment-banner-text-content');
+			}
 		}
 
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="test-red"]/stylesheets/stylesheet[@id="environment-banner"]');
-		$this->RemoveNodeFromXPath('/itop_design/branding/themes/theme[@id="test-red"]/stylesheets/stylesheet[@id="fullmoon"]');
-
 		// Add new attribute to theme import nodes
 		
 		$oNodeList = $oXPath->query('/itop_design/branding/themes/theme/imports/import');