diff --git a/browser/css/light.css b/browser/css/light.css
index 1d4d111701c627730adf4b5c1f01fb530dd1a449..f722cf02c64bddaada58695875cef7a94d09ce49 100644
--- a/browser/css/light.css
+++ b/browser/css/light.css
@@ -53,7 +53,7 @@ ul {
 #top-container {
   height: 32px;
   width: 100%;
-  background: #ffffff;
+  background: #9fe855;
   position: fixed;
   z-index: 1;
 }
diff --git a/doc/dev.org b/doc/dev.org
index f38a3224726d40b155a73c16fe07033759543b73..bcdbc8269a5123b466a10f9044d9bb3e5a9c9924 100644
--- a/doc/dev.org
+++ b/doc/dev.org
@@ -283,13 +283,24 @@ The cache is stored for each user and is updated only when a change occurs (mess
     [[../browser/test/QUnit/testFiles][browser/test/QUnit/testFiles]]. The file [[../browser/test/QUnit/testFiles/data_test.js][data_test.js]] contains a toy
     dataset that is used in the tests.
 
-    Unit tests can be launched using a real browser (instead of phantomjs). It
+    Unit tests can be launched using a real browser (instead of nightmare). It
     suffices to open the file [[../browser/test/QUnit/test_Qunit.html][test_Qunit.html]]. In this HTML webpage it is
     possible to see the coverage. It is important that all possible functions
     are covered by unit tests. Having the coverage displayed under Firefox
     needs to display the webpage using a web server for security
     reasons. Under Chromium/Chrome this should work fine by just opening the
     webpage.
+
+**** Installation
+     Nightmare is distributed withing =node= and can therefore be installed with it.
+
+     #+BEGIN_SRC sh
+     apt-get install nodejs npm
+     npm install nightmare
+     #+END_SRC
+
+     Note that using =nightmare= for our unit testing
+     requires the installation of =xvfb=.
 *** Functional
 
 **** Architecture
@@ -351,8 +362,19 @@ gem install test-unit
 #+END_SRC
 
 This may install a =selenium-webdriver= gem whose version is ≥ 3. We highly
-recommend that you force an install to a version < 3 (/e.g./ 2.53.4). However
-the webdriver may not work with recent versions of Firefox (> 45).
+recommend that you force an install to a version < 3 (/e.g./ 2.53.4).
+
+#+BEGIN_SRC sh
+# Removing a new version of selenium-webdriver
+gem uninstall selenium-webdriver
+# Installing an older version
+gem install selenium-webdriver -v 2.53.4
+#+END_SRC
+
+However the webdriver may not work with recent versions of Firefox (> 45).  In
+such a case you would like to downgrade your Firefox version or use a former
+version. The Firefox version used can be set with an environment variable (see
+below). All Firefox releases are [[https://download-installer.cdn.mozilla.net/pub/firefox/releases/ ][available here]].
 
 **** Launch browser tests
 
diff --git a/doc/server.org b/doc/server.org
index 0b625981a1866e7f7817ea82aec560ada885780f..02d8017e95889d012fa741cf30aa4baf4b7618ca 100644
--- a/doc/server.org
+++ b/doc/server.org
@@ -97,7 +97,7 @@ These instructions are preliminary, other documentation can also be found in [[h
     apt-get install g++
     apt-get install make
     apt-get install unzip
-    apt-get install enum34
+    apt-get install python-pip python-enum34
    #+END_SRC
 
 ** Vidjil server installation and initialization