Index: app/views/projects/_form.rhtml
===================================================================
--- app/views/projects/_form.rhtml	(revision 846)
+++ app/views/projects/_form.rhtml	(working copy)
@@ -12,6 +12,9 @@
 <p><%= f.text_field :identifier, :required => true, :size => 15, :disabled => @project.identifier_frozen? %><br /><em><%= l(:text_length_between, 3, 12) %> <%= l(:text_project_identifier_info) unless @project.identifier_frozen? %></em></p>
 <p><%= f.text_field :homepage, :size => 40 %></p>
 <p><%= f.check_box :is_public %></p>
+<p><label><%= l(:label_theme) %></label>
+<%= select_tag 'project[ui_theme]', options_for_select( ([[l(:label_default), '']] + Redmine::Themes.themes.collect {|t| [t.name, t.id]}), @project.ui_theme) %></p>
+
 <%= wikitoolbar_for 'project_description' %>
 
 <% for @custom_value in @custom_values %>
Index: lib/redmine/themes.rb
===================================================================
--- lib/redmine/themes.rb	(revision 846)
+++ lib/redmine/themes.rb	(working copy)
@@ -65,7 +65,8 @@
 
 module ApplicationHelper
   def stylesheet_path(source)
-    @current_theme ||= Redmine::Themes.theme(Setting.ui_theme)
+    project_theme = Redmine::Themes.theme(@project.ui_theme) unless @project.nil?
+    @current_theme ||= project_theme ||= Redmine::Themes.theme(Setting.ui_theme)
     super((@current_theme && @current_theme.stylesheets.include?(source)) ?
       "/themes/#{@current_theme.dir}/stylesheets/#{source}" : source)
   end