diff --git a/app/assets/stylesheets/common.scss b/app/assets/stylesheets/common.scss
index 35c5ba845..fc774a3ee 100644
--- a/app/assets/stylesheets/common.scss
+++ b/app/assets/stylesheets/common.scss
@@ -66,12 +66,6 @@ time[title] {
   color: $blue;
 }
 
-/* Rules for borders */
-/* These add additional colours to those provided by bootstrap */
-.border-grey {
-  border-color: $grey !important;
-}
-
 /* Rules for the header */
 
 #menu-icon {
diff --git a/app/helpers/user_helper.rb b/app/helpers/user_helper.rb
index e1ab423a1..cf2d40da5 100644
--- a/app/helpers/user_helper.rb
+++ b/app/helpers/user_helper.rb
@@ -2,7 +2,7 @@ module UserHelper
   # User images
 
   def user_image(user, options = {})
-    options[:class] ||= "user_image border border-grey"
+    options[:class] ||= "user_image border border-secondary-subtle"
     options[:alt] ||= ""
 
     if user.image_use_gravatar
@@ -15,7 +15,7 @@ module UserHelper
   end
 
   def user_thumbnail(user, options = {})
-    options[:class] ||= "user_thumbnail border border-grey"
+    options[:class] ||= "user_thumbnail border border-secondary-subtle"
     options[:alt] ||= ""
 
     if user.image_use_gravatar
@@ -28,7 +28,7 @@ module UserHelper
   end
 
   def user_thumbnail_tiny(user, options = {})
-    options[:class] ||= "user_thumbnail_tiny border border-grey"
+    options[:class] ||= "user_thumbnail_tiny border border-secondary-subtle"
     options[:alt] ||= ""
 
     if user.image_use_gravatar
diff --git a/app/views/browse/_tag.html.erb b/app/views/browse/_tag.html.erb
index c0cdb5f9a..578dc8b59 100644
--- a/app/views/browse/_tag.html.erb
+++ b/app/views/browse/_tag.html.erb
@@ -1,4 +1,4 @@
 <tr>
-  <th class='py-1 border-grey table-light fw-normal' dir='auto'><%= format_key(tag[0]) %></th>
-  <td class='py-1 border-grey border-start' dir='auto'><%= format_value(tag[0], tag[1]) %></td>
+  <th class='py-1 border-secondary-subtle table-light fw-normal' dir='auto'><%= format_key(tag[0]) %></th>
+  <td class='py-1 border-secondary-subtle border-start' dir='auto'><%= format_value(tag[0], tag[1]) %></td>
 </tr>
diff --git a/app/views/browse/_tag_details.html.erb b/app/views/browse/_tag_details.html.erb
index cc08fe16a..2b4ec1bb0 100644
--- a/app/views/browse/_tag_details.html.erb
+++ b/app/views/browse/_tag_details.html.erb
@@ -1,6 +1,6 @@
 <% unless tag_details.empty? %>
   <h4><%= t ".tags" %></h4>
-  <div class='mb-3 border border-grey rounded overflow-hidden'>
+  <div class='mb-3 border border-secondary-subtle rounded overflow-hidden'>
     <table class='mb-0 browse-tag-list table align-middle text-break'>
       <%= render :partial => "browse/tag", :collection => tag_details.sort %>
     </table>
diff --git a/app/views/dashboards/show.html.erb b/app/views/dashboards/show.html.erb
index 744661dfd..d3e6dbcb3 100644
--- a/app/views/dashboards/show.html.erb
+++ b/app/views/dashboards/show.html.erb
@@ -6,7 +6,7 @@
   <% if current_user and @user.id == current_user.id %>
     <div class="col-md order-md-last">
       <% if !@user.home_location? %>
-        <div id="map" class="content_map border border-grey">
+        <div id="map" class="content_map border border-secondary-subtle">
           <p class="m-3"><%= t(".no_home_location_html", :edit_profile_link => link_to(t(".edit_your_profile"), edit_profile_path)) %></p>
         </div>
       <% else %>
@@ -19,7 +19,7 @@
              :icon => image_path("marker-red.png"),
              :description => render(:partial => "popup", :object => current_user, :locals => { :type => "your location" })
            } %>
-        <%= tag.div "", :id => "map", :class => "content_map border border-grey rounded", :data => { :user => user_data } %>
+        <%= tag.div "", :id => "map", :class => "content_map border border-secondary-subtle rounded", :data => { :user => user_data } %>
       <% end %>
 
       <% friends = @user.friends %>
diff --git a/app/views/diary_entries/_diary_entry.html.erb b/app/views/diary_entries/_diary_entry.html.erb
index a25ef10db..9c7d7b2dc 100644
--- a/app/views/diary_entries/_diary_entry.html.erb
+++ b/app/views/diary_entries/_diary_entry.html.erb
@@ -1,4 +1,4 @@
-<article class='diary_post border-top border-grey py-3<%= " text-muted px-3 bg-danger bg-opacity-10" unless diary_entry.visible %> user_<%= diary_entry.user.id %>'>
+<article class='diary_post border-top border-secondary-subtle py-3<%= " text-muted px-3 bg-danger bg-opacity-10" unless diary_entry.visible %> user_<%= diary_entry.user.id %>'>
   <%= render :partial => "diary_entry_heading", :object => diary_entry, :as => "diary_entry" %>
 
   <div class="richtext text-break" xml:lang="<%= diary_entry.language_code %>" lang="<%= diary_entry.language_code %>">
diff --git a/app/views/diary_entries/_form.html.erb b/app/views/diary_entries/_form.html.erb
index 0b38e3ea6..291e8e33b 100644
--- a/app/views/diary_entries/_form.html.erb
+++ b/app/views/diary_entries/_form.html.erb
@@ -5,7 +5,7 @@
 <fieldset>
   <legend><%= t ".location" -%></legend>
 
-  <%= tag.div "", :id => "map", :class => "border border-grey rounded mb-3", :data => { :lat => @lat, :lon => @lon, :zoom => @zoom } %>
+  <%= tag.div "", :id => "map", :class => "border border-secondary-subtle rounded mb-3", :data => { :lat => @lat, :lon => @lon, :zoom => @zoom } %>
 
   <div class="row mb-3">
     <%= f.text_field :latitude, :wrapper_class => "col-sm-4 d-flex flex-column", :class => "mt-auto", :id => "latitude" %>
diff --git a/app/views/diary_entries/show.html.erb b/app/views/diary_entries/show.html.erb
index 0aea2d442..6c0895380 100644
--- a/app/views/diary_entries/show.html.erb
+++ b/app/views/diary_entries/show.html.erb
@@ -13,7 +13,7 @@
 <%= render @entry %>
 
 <div id="comments" class="comments mb-3 overflow-hidden">
-  <div class="row border-bottom border-grey">
+  <div class="row border-bottom border-secondary-subtle">
     <h2 class="col"><%= t(".discussion") %></h2>
 
     <% if current_user %>
diff --git a/app/views/layouts/_header.html.erb b/app/views/layouts/_header.html.erb
index 97be3f7b8..0fafc3c7f 100644
--- a/app/views/layouts/_header.html.erb
+++ b/app/views/layouts/_header.html.erb
@@ -81,7 +81,7 @@
     </ul>
     <% if current_user && current_user.id %>
       <div class='d-inline-flex dropdown user-menu logged-in'>
-        <button class='dropdown-toggle btn btn-outline-secondary border-grey bg-white text-secondary px-2 py-1 flex-grow-1' type='button' data-bs-toggle='dropdown'>
+        <button class='dropdown-toggle btn btn-outline-secondary border-secondary-subtle bg-white text-secondary px-2 py-1 flex-grow-1' type='button' data-bs-toggle='dropdown'>
           <%= user_thumbnail_tiny(current_user, :width => 25, :height => 25, :class => "user_thumbnail_tiny rounded-1") %>
           <%= render :partial => "layouts/inbox" %>
           <span class="user-button">
diff --git a/app/views/messages/show.html.erb b/app/views/messages/show.html.erb
index 29bf02cd8..8fe508469 100644
--- a/app/views/messages/show.html.erb
+++ b/app/views/messages/show.html.erb
@@ -2,7 +2,7 @@
   <h1><%= @message.title %></h1>
 <% end %>
 
-<div class='mb-3 border-bottom border-grey py-1 d-flex gap-1 flex-wrap'>
+<div class='mb-3 border-bottom border-secondary-subtle py-1 d-flex gap-1 flex-wrap'>
   <% if current_user == @message.recipient %>
     <%= user_thumbnail_tiny @message.sender %>
     <%= link_to @message.sender.display_name, @message.sender %>
diff --git a/app/views/profiles/edit.html.erb b/app/views/profiles/edit.html.erb
index 47282d5a2..d755be52c 100644
--- a/app/views/profiles/edit.html.erb
+++ b/app/views/profiles/edit.html.erb
@@ -56,7 +56,7 @@
       <input class="form-check-input" type="checkbox" name="updatehome" value="1" <% unless current_user.home_location? %> checked <% end %> id="updatehome" />
       <label class="form-check-label" for="updatehome"><%= t ".update home location on click" %></label>
     </div>
-    <%= tag.div "", :id => "map", :class => "content_map set_location border border-grey rounded" %>
+    <%= tag.div "", :id => "map", :class => "content_map set_location border border-secondary-subtle rounded" %>
   </fieldset>
 
   <%= f.primary t(".save") %>
diff --git a/app/views/site/export.html.erb b/app/views/site/export.html.erb
index bb66c665a..3bc62883f 100644
--- a/app/views/site/export.html.erb
+++ b/app/views/site/export.html.erb
@@ -6,7 +6,7 @@
   <%= hidden_field_tag "format", "osm", :autocomplete => "off" %>
 
   <div class='export_area_inputs'>
-    <div class='export_boxy border border-grey rounded'>
+    <div class='export_boxy border border-secondary-subtle rounded'>
       <%= text_field_tag("maxlat", nil, :size => 10, :autocomplete => "off", :class => "export_bound form-control mx-auto") %>
       <div class="clearfix">
         <%= text_field_tag("minlon", nil, :size => 10, :autocomplete => "off", :class => "export_bound form-control my-2") %>
diff --git a/app/views/users/terms.html.erb b/app/views/users/terms.html.erb
index e2ece8f1a..340aaf04e 100644
--- a/app/views/users/terms.html.erb
+++ b/app/views/users/terms.html.erb
@@ -30,7 +30,7 @@
     <% end %>
   </div>
 
-  <div id="contributorTerms" class="legale border border-grey rounded">
+  <div id="contributorTerms" class="legale border border-secondary-subtle rounded">
     <%= render :partial => "terms" %>
   </div>
 
diff --git a/test/helpers/user_helper_test.rb b/test/helpers/user_helper_test.rb
index 0767dea56..e72887798 100644
--- a/test/helpers/user_helper_test.rb
+++ b/test/helpers/user_helper_test.rb
@@ -8,12 +8,12 @@ class UserHelperTest < ActionView::TestCase
     gravatar_user = create(:user, :image_use_gravatar => true)
 
     image = user_image(user)
-    assert_match %r{^<img class="user_image border border-grey" .* src="/images/avatar_large.png" />$}, image
+    assert_match %r{^<img class="user_image border border-secondary-subtle" .* src="/images/avatar_large.png" />$}, image
 
     image = user_image(user, :class => "foo")
     assert_match %r{^<img class="foo" .* src="/images/avatar_large.png" />$}, image
     image = user_image(gravatar_user)
-    assert_match %r{^<img class="user_image border border-grey" .* src="http://www.gravatar.com/avatar/.*" />$}, image
+    assert_match %r{^<img class="user_image border border-secondary-subtle" .* src="http://www.gravatar.com/avatar/.*" />$}, image
 
     image = user_image(gravatar_user, :class => "foo")
     assert_match %r{^<img class="foo" .* src="http://www.gravatar.com/avatar/.*" />$}, image
@@ -24,13 +24,13 @@ class UserHelperTest < ActionView::TestCase
     gravatar_user = create(:user, :image_use_gravatar => true)
 
     image = user_thumbnail(user)
-    assert_match %r{^<img class="user_thumbnail border border-grey" .* src="/images/avatar_small.png" />$}, image
+    assert_match %r{^<img class="user_thumbnail border border-secondary-subtle" .* src="/images/avatar_small.png" />$}, image
 
     image = user_thumbnail(user, :class => "foo")
     assert_match %r{^<img class="foo" .* src="/images/avatar_small.png" />$}, image
 
     image = user_thumbnail(gravatar_user)
-    assert_match %r{^<img class="user_thumbnail border border-grey" .* src="http://www.gravatar.com/avatar/.*" />$}, image
+    assert_match %r{^<img class="user_thumbnail border border-secondary-subtle" .* src="http://www.gravatar.com/avatar/.*" />$}, image
 
     image = user_thumbnail(gravatar_user, :class => "foo")
     assert_match %r{^<img class="foo" .* src="http://www.gravatar.com/avatar/.*" />$}, image
@@ -41,13 +41,13 @@ class UserHelperTest < ActionView::TestCase
     gravatar_user = create(:user, :image_use_gravatar => true)
 
     image = user_thumbnail_tiny(user)
-    assert_match %r{^<img class="user_thumbnail_tiny border border-grey" .* src="/images/avatar_small.png" />$}, image
+    assert_match %r{^<img class="user_thumbnail_tiny border border-secondary-subtle" .* src="/images/avatar_small.png" />$}, image
 
     image = user_thumbnail_tiny(user, :class => "foo")
     assert_match %r{^<img class="foo" .* src="/images/avatar_small.png" />$}, image
 
     image = user_thumbnail_tiny(gravatar_user)
-    assert_match %r{^<img class="user_thumbnail_tiny border border-grey" .* src="http://www.gravatar.com/avatar/.*" />$}, image
+    assert_match %r{^<img class="user_thumbnail_tiny border border-secondary-subtle" .* src="http://www.gravatar.com/avatar/.*" />$}, image
 
     image = user_thumbnail_tiny(gravatar_user, :class => "foo")
     assert_match %r{^<img class="foo" .* src="http://www.gravatar.com/avatar/.*" />$}, image