diff --git a/app/assets/stylesheets/color_themes/dark_green.scss b/app/assets/stylesheets/color_themes/dark_green.scss
new file mode 100644
index 000000000..2570d2aa7
--- /dev/null
+++ b/app/assets/stylesheets/color_themes/dark_green.scss
@@ -0,0 +1,6 @@
+body > header {
+  background: rgb(0,35,0);
+  box-shadow: 0 1px 3px rgba(0,0,0,0.9),
+              0 25px 35px -30px rgba(255,255,255,0.4) inset;
+  border-color: rgb(0,35,0);
+}
diff --git a/app/assets/stylesheets/color_themes/original.scss b/app/assets/stylesheets/color_themes/original.scss
new file mode 100644
index 000000000..d20e293eb
--- /dev/null
+++ b/app/assets/stylesheets/color_themes/original.scss
@@ -0,0 +1,5 @@
+body > header {
+  background: rgb(30,30,30);
+  box-shadow: 0 1px 3px rgba(0,0,0,0.9),
+              0 25px 30px -25px rgba(255,255,255,0.4) inset;
+}
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index eaa03b62b..f929728ae 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -69,6 +69,12 @@ class UsersController < ApplicationController
         else
           flash[:error] = I18n.t 'users.update.follow_settings_not_changed'
         end
+      elsif u[:color_theme]
+        if @user.update_attributes(u)
+          flash[:notice] = I18n.t "users.update.color_theme_changed"
+        else
+          flash[:error] = I18n.t "users.update.color_theme_not_changed"
+        end
       end
     end
     set_email_preferences
@@ -181,6 +187,7 @@ class UsersController < ApplicationController
       :password,
       :password_confirmation,
       :language,
+      :color_theme,
       :disable_mail,
       :invitation_service,
       :invitation_identifier,
diff --git a/app/helpers/users_helper.rb b/app/helpers/users_helper.rb
index 0b81a4a3d..f19556686 100644
--- a/app/helpers/users_helper.rb
+++ b/app/helpers/users_helper.rb
@@ -6,4 +6,48 @@ module UsersHelper
   def owner_image_link
     person_image_link(current_user.person, :size => :thumb_small)
   end
+
+  # Returns the path of the current color theme so that it
+  # can be loaded in app/views/layouts/application.html.haml
+  # and app/views/layouts/application.mobile.haml. If the user
+  # is not signed in or has not specified a color theme, the
+  # default (original) color theme is loaded.
+  #
+  # ==== Examples
+  #
+  #   # if user is not signed in
+  #   current_color_theme # => "color_themes/original"
+  #   # if user Alice has not selected a color theme
+  #   current_color_theme # => "color_themes/original"
+  #   # if user Alice has selected a "magenta" theme
+  #   current_color_theme # => "color_themes/magenta"
+  def current_color_theme
+    if user_signed_in?
+      color_theme = current_user.color_theme
+    end
+    color_theme ||= DEFAULT_COLOR_THEME
+    current_color_theme = "color_themes/" + color_theme
+  end
+
+  # Returns an array of the color themes available, as
+  # specified from AVAILABLE_COLOR_THEMES in
+  # config/initializers/color_themes.rb.
+  #
+  # ==== Examples
+  #
+  #   # if config/color_themes.yml is:
+  #   available:
+  #     original: "Original dark"
+  #     dark_green: "Dark green"
+  #   # and AVAILABLE_COLOR_THEMES is accordingly initialized,
+  #   # then:
+  #   available_color_themes
+  #   # => [["Original dark", "original"], ["Dark green", "dark_green"]]
+  def available_color_themes
+    opts = []
+    AVAILABLE_COLOR_THEMES.each do |theme_code, theme_name|
+      opts << [theme_name, theme_code]
+    end
+    opts
+  end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 8e569df21..41c51af51 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -23,12 +23,14 @@ class User < ActiveRecord::Base
 
   before_validation :strip_and_downcase_username
   before_validation :set_current_language, :on => :create
+  before_validation :set_default_color_theme, :on => :create
 
   validates :username, :presence => true, :uniqueness => true
   validates_format_of :username, :with => /\A[A-Za-z0-9_]+\z/
   validates_length_of :username, :maximum => 32
   validates_exclusion_of :username, :in => AppConfig.settings.username_blacklist
   validates_inclusion_of :language, :in => AVAILABLE_LANGUAGE_CODES
+  validates_inclusion_of :color_theme, :in => AVAILABLE_COLOR_THEME_CODES, :allow_blank => true
   validates_format_of :unconfirmed_email, :with  => Devise.email_regexp, :allow_blank => true
 
   validates_presence_of :person, :unless => proc {|user| user.invitation_token.present?}
@@ -198,6 +200,10 @@ class User < ActiveRecord::Base
     self.language = I18n.locale.to_s if self.language.blank?
   end
 
+  def set_default_color_theme
+    self.color_theme ||= DEFAULT_COLOR_THEME
+  end
+
   # This override allows a user to enter either their email address or their username into the username field.
   # @return [User] The user that matches the username/email condition.
   # @return [nil] if no user matches that condition.
@@ -428,6 +434,8 @@ class User < ActiveRecord::Base
     self.email = opts[:email]
     self.language = opts[:language]
     self.language ||= I18n.locale.to_s
+    self.color_theme = opts[:color_theme]
+    self.color_theme ||= DEFAULT_COLOR_THEME
     self.valid?
     errors = self.errors
     errors.delete :person
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index e40ee1abd..d4f6a3948 100644
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -26,6 +26,8 @@
     - if rtl?
       = stylesheet_link_tag :rtl, media:  'all'
 
+    = stylesheet_link_tag current_color_theme, :media => "all"
+
     = old_browser_js_support
     <!--[if IE]>
     = javascript_include_tag :ie
diff --git a/app/views/users/_edit.haml b/app/views/users/_edit.haml
index 381e46dc7..20d64468a 100644
--- a/app/views/users/_edit.haml
+++ b/app/views/users/_edit.haml
@@ -61,6 +61,14 @@
 
       %hr
 
+      %h3= t(".change_color_theme")
+      = form_for "user", url: user_path, html: {method: :put} do |f|
+        .form-inline.clearfix
+          = f.select :color_theme, available_color_themes, {}, {class: "form-control form-group"}
+          = f.submit t(".change_color_theme"), class: "btn btn-primary pull-right"
+
+      %hr
+
       %h3#stream-preferences
         = t('.stream_preferences')
       = form_for current_user, url: user_path, html: { method: :put } do |f|
diff --git a/config/application.rb b/config/application.rb
index 0c8111377..83965ea13 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -87,6 +87,7 @@ module Diaspora
       mobile/mobile.css
       rtl.css
       home.css
+      color_themes/*.css
     }
 
     # Version of your assets, change this if you want to expire all your assets
diff --git a/config/color_themes.yml b/config/color_themes.yml
new file mode 100644
index 000000000..5cb8d8c56
--- /dev/null
+++ b/config/color_themes.yml
@@ -0,0 +1,3 @@
+available:
+  original: "Original dark"
+  dark_green: "Dark green"
diff --git a/config/initializers/color_themes.rb b/config/initializers/color_themes.rb
new file mode 100644
index 000000000..b981d19ff
--- /dev/null
+++ b/config/initializers/color_themes.rb
@@ -0,0 +1,18 @@
+require 'pathname'
+
+# Generate the path to the .yml file with the available color themes.
+color_themes_file = Pathname.new(__FILE__).dirname.join('..').expand_path.join("color_themes.yml")
+# Check in case config/color_themes.yml does not exist.
+if color_themes_file.exist?
+  # Load the file specified by the generated path.
+  color_themes = YAML.load_file(color_themes_file)
+  # If the file contains one or more color themes, include them in AVAILABLE_COLOR_THEMES, else include the original theme.
+  AVAILABLE_COLOR_THEMES = (color_themes["available"].length > 0) ? color_themes["available"] : { "original" => "original.scss" }
+else
+  AVAILABLE_COLOR_THEMES = { "original" => "original.scss" }
+end
+# Get all codes from available themes into a separate variable, so that they can be called easier.
+AVAILABLE_COLOR_THEME_CODES = AVAILABLE_COLOR_THEMES.keys
+
+# The default color theme, that will be called when no color theme is specified.
+DEFAULT_COLOR_THEME = "original"
diff --git a/config/locales/diaspora/en.yml b/config/locales/diaspora/en.yml
index 143781b35..1b69bbf35 100644
--- a/config/locales/diaspora/en.yml
+++ b/config/locales/diaspora/en.yml
@@ -1323,6 +1323,7 @@ en:
       current_password_expl: "the one you sign in with..."
       character_minimum_expl: "must be at least six characters"
       change_language: "Change language"
+      change_color_theme: "Change color theme"
       close_account_text: "Close account"
       stream_preferences: "Stream preferences"
       show_community_spotlight: "Show “community spotlight” in stream"
@@ -1401,6 +1402,8 @@ en:
       unconfirmed_email_not_changed: "Email change failed"
       follow_settings_changed: "Follow settings changed"
       follow_settings_not_changed: "Follow settings change failed."
+      color_theme_changed: "Color theme successfully changed."
+      color_theme_not_changed: "An error occurred while changing the color theme."
     public:
       does_not_exist: "User %{username} does not exist!"
     confirm_email:
diff --git a/db/migrate/20150523004437_enable_color_themes.rb b/db/migrate/20150523004437_enable_color_themes.rb
new file mode 100644
index 000000000..d9cea868d
--- /dev/null
+++ b/db/migrate/20150523004437_enable_color_themes.rb
@@ -0,0 +1,9 @@
+class EnableColorThemes < ActiveRecord::Migration
+  def up
+    add_column(:users, :color_theme, :string)
+  end
+
+  def down
+    remove_column(:users, :color_theme)
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 08c88be2f..90367fa20 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -566,6 +566,7 @@ ActiveRecord::Schema.define(version: 20150531005120) do
     t.string   "exported_photos_file",               limit: 255
     t.datetime "exported_photos_at"
     t.boolean  "exporting_photos",                                 default: false
+    t.string   "color_theme",                        limit: 255
   end
 
   add_index "users", ["authentication_token"], name: "index_users_on_authentication_token", unique: true, using: :btree
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 517cacd85..c447ec4e2 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -1009,6 +1009,7 @@ describe User, :type => :model do
           unconfirmed_email
           confirm_email_token
           last_seen
+          color_theme
         }.sort)
       end
     end