diff --git a/app/views/shared_mailers/_social.html.haml b/app/views/shared_mailers/_social.html.haml
index 0810dc874..86b9974be 100644
--- a/app/views/shared_mailers/_social.html.haml
+++ b/app/views/shared_mailers/_social.html.haml
@@ -8,12 +8,14 @@
           %td
 
             %h5 Connect with us:
+            -# background-color is inlined on each link because email clients only
+            -# reliably render inline styles; see issue #2634
             %p
-              %a{ href: "https://slack.codebar.io/", class: 'soc-btn sl'} Join us on Slack
-              %a{ href: "https://www.linkedin.com/company/codebarcommunity", class: "soc-btn li" } Follow us on LinkedIn
-              %a{ href: "https://www.facebook.com/codebarHQ", class: 'soc-btn fb'} Follow us on Facebook
-              %a{ href: "https://bsky.app/profile/codebar.bsky.social", class: "soc-btn bs" } Follow us on Bluesky
-              %a{ href: "https://www.youtube.com/channel/UCEYz232agE47GHUq8wneBCA", class: "soc-btn yt" } Follow us on YouTube
+              %a{ href: "https://slack.codebar.io/", class: 'soc-btn sl', style: 'background-color: #2EB67D;' } Join us on Slack
+              %a{ href: "https://www.linkedin.com/company/codebarcommunity", class: "soc-btn li", style: 'background-color: #0077B5;' } Follow us on LinkedIn
+              %a{ href: "https://www.facebook.com/codebarHQ", class: 'soc-btn fb', style: 'background-color: #3B5998;' } Follow us on Facebook
+              %a{ href: "https://bsky.app/profile/codebar.bsky.social", class: "soc-btn bs", style: 'background-color: #1daced;' } Follow us on Bluesky
+              %a{ href: "https://www.youtube.com/channel/UCEYz232agE47GHUq8wneBCA", class: "soc-btn yt", style: 'background-color: #FF0000;' } Follow us on YouTube
              
 
 
diff --git a/spec/mailers/workshop_invitation_mailer_spec.rb b/spec/mailers/workshop_invitation_mailer_spec.rb
index ba0241b8a..0584a2f81 100644
--- a/spec/mailers/workshop_invitation_mailer_spec.rb
+++ b/spec/mailers/workshop_invitation_mailer_spec.rb
@@ -110,6 +110,17 @@
     expect(email.body.encoded).to match(workshop.chapter.email)
   end
 
+  it '#invite_student renders social links with inline background colours' do
+    # asserts on the template output before premailer runs, so the colours
+    # don't depend on email.css being resolved (see issue #2634)
+    mail = described_class.invite_student(workshop, member, invitation)
+
+    html = mail.body.decoded
+    ['#2EB67D', '#0077B5', '#3B5998', '#1daced', '#FF0000'].each do |colour|
+      expect(html).to include("background-color: #{colour}")
+    end
+  end
+
   it '#attending renders workshop description as HTML, not escaped' do
     description = '<strong>Important notice:</strong> Please bring a laptop.'
     workshop = Fabricate(:workshop, description: description)