diff --git a/app/views/users/_customization.html.erb b/app/views/users/_customization.html.erb
index f4d163d90..1062329a4 100644
--- a/app/views/users/_customization.html.erb
+++ b/app/views/users/_customization.html.erb
@@ -14,7 +14,8 @@
     <fieldset class="crayons-field">
       <legend class="crayons-field__label">Site Theme</legend>
       <div class="theme-selector-field grid gap-4 grid-cols-2 l:grid-cols-3">
-        <% Users::Setting.config_themes.keys.each do |theme| %>
+        <%# This is temporary while we're migrating themes %>
+        <% %w[light_theme dark_theme].each do |theme| %>
           <%= render partial: "theme_selector", locals: { f: f, theme: theme } %>
         <% end %>
       </div>
diff --git a/db/migrate/20211021063645_add_prefer_os_color_scheme_to_user_settings.rb b/db/migrate/20211021063645_add_prefer_os_color_scheme_to_user_settings.rb
new file mode 100644
index 000000000..ec0c33c2b
--- /dev/null
+++ b/db/migrate/20211021063645_add_prefer_os_color_scheme_to_user_settings.rb
@@ -0,0 +1,5 @@
+class AddPreferOsColorSchemeToUserSettings < ActiveRecord::Migration[6.1]
+  def change
+    add_column :users_settings, :prefer_os_color_scheme, :boolean, default: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 940533ad7..695670f03 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1419,6 +1419,7 @@ ActiveRecord::Schema.define(version: 2021_11_04_161101) do
     t.string "inbox_guidelines"
     t.integer "inbox_type", default: 0, null: false
     t.boolean "permit_adjacent_sponsors", default: true
+    t.boolean "prefer_os_color_scheme", default: true
     t.datetime "updated_at", precision: 6, null: false
     t.bigint "user_id", null: false
     t.index ["feed_url"], name: "index_users_settings_on_feed_url", where: "((COALESCE(feed_url, ''::character varying))::text <> ''::text)"
diff --git a/lib/data_update_scripts/20211019063703_migrate_themes.rb b/lib/data_update_scripts/20211019063703_migrate_themes.rb
new file mode 100644
index 000000000..7face4786
--- /dev/null
+++ b/lib/data_update_scripts/20211019063703_migrate_themes.rb
@@ -0,0 +1,22 @@
+module DataUpdateScripts
+  class MigrateThemes
+    FILE_NAME = "20211019063703_migrate_themes".freeze
+
+    def run
+      # NOTE: I couldn't come up with a better way to make this idempotent.
+      return if DataUpdateScript.where(file_name: FILE_NAME).any?
+
+      # No OS sync for Dark (2) users
+      Users::Setting.where(config_theme: 2).update_all(prefer_os_color_scheme: false)
+
+      # Ten X Hacker (4) -> Dark (2), no OS sync
+      Users::Setting.where(config_theme: 4).update_all(config_theme: 2, prefer_os_color_scheme: false)
+
+      # Minimal (1) -> Light (0), no OS sync
+      Users::Setting.where(config_theme: 1).update_all(config_theme: 0, prefer_os_color_scheme: false)
+
+      # Pink (3) -> Light (0), OS sync (defaults to true), the
+      Users::Setting.where(config_theme: 3).update_all(config_theme: 0)
+    end
+  end
+end
diff --git a/spec/lib/data_update_scripts/migrate_themes_spec.rb b/spec/lib/data_update_scripts/migrate_themes_spec.rb
new file mode 100644
index 000000000..4f57b78ae
--- /dev/null
+++ b/spec/lib/data_update_scripts/migrate_themes_spec.rb
@@ -0,0 +1,48 @@
+require "rails_helper"
+require Rails.root.join(
+  "lib/data_update_scripts/20211019063703_migrate_themes.rb",
+)
+
+describe DataUpdateScripts::MigrateThemes do
+  let(:user) { create(:user) }
+
+  it "leaves default theme users on light and leaves OS sync enabled" do
+    user.setting.update_columns(config_theme: 0)
+
+    expect { described_class.new.run }
+      .to not_change { user.setting.reload.config_theme }.from("light_theme")
+      .and not_change { user.setting.prefer_os_color_scheme }.from(true)
+  end
+
+  it "updates minimal theme users to light and disables OS sync" do
+    user.setting.update_columns(config_theme: 1)
+
+    expect { described_class.new.run }
+      .to change { user.setting.reload.config_theme }.to("light_theme")
+      .and change { user.setting.prefer_os_color_scheme }.from(true).to(false)
+  end
+
+  it "updates night theme users to dark and disables OS sync" do
+    user.setting.update_columns(config_theme: 2)
+
+    expect { described_class.new.run }
+      .to not_change { user.setting.reload.config_theme }.from("dark_theme")
+      .and change { user.setting.prefer_os_color_scheme }.from(true).to(false)
+  end
+
+  it "updates pink theme users to light and leaves OS sync enabled" do
+    user.setting.update_columns(config_theme: 3)
+
+    expect { described_class.new.run }
+      .to change { user.setting.reload.config_theme }.to("light_theme")
+      .and not_change { user.setting.prefer_os_color_scheme }.from(true)
+  end
+
+  it "updates ten x hacker theme users to dark and disables OS sync" do
+    user.setting.update_columns(config_theme: 4)
+
+    expect { described_class.new.run }
+      .to change { user.setting.reload.config_theme }.to("dark_theme")
+      .and change { user.setting.prefer_os_color_scheme }.from(true).to(false)
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index e58e02977..55ec6b233 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -21,6 +21,7 @@ require "zonebie/rspec"
 # This makes Rspec fail if there's any output
 RSpec::Matchers.define_negated_matcher :avoid_outputting, :output
 RSpec::Matchers.define_negated_matcher :exclude, :include
+RSpec::Matchers.define_negated_matcher :not_change, :change
 ############
 RSpec.configure do |config|
   # makes example fail if there's any output
diff --git a/spec/system/user/user_edits_customization_spec.rb b/spec/system/user/user_edits_customization_spec.rb
index 57e08b531..cd0bd0c72 100644
--- a/spec/system/user/user_edits_customization_spec.rb
+++ b/spec/system/user/user_edits_customization_spec.rb
@@ -13,7 +13,7 @@ RSpec.describe "User edits their Customization settings", type: :system do
     it "makes the 'Save Button' footer sticky once a theme is selected", js: true do
       expect(page).not_to have_css(".sticky")
 
-      choose("Ten X Hacker Theme")
+      choose("Dark Theme")
 
       expect(page).to have_css(".sticky")
     end