Use CSS custom properties for warning color

Use CSS custom properties for warning color

diff --git a/assets/stylesheets/colors.scss b/assets/stylesheets/colors.scss
new file mode 100644
index 0000000..7cea91a
--- /dev/null
+++ b/assets/stylesheets/colors.scss
@@ -0,0 +1,3 @@
+:root {
+  --encrypt-warn: #{mix($danger, #ffff00)};
+}
diff --git a/assets/stylesheets/common/encrypt.scss b/assets/stylesheets/common/encrypt.scss
index 25535e7..097dde9 100644
--- a/assets/stylesheets/common/encrypt.scss
+++ b/assets/stylesheets/common/encrypt.scss
@@ -93,7 +93,7 @@ pre.exported-key-pair {
   }
 
   &.integrity-warn {
-    color: mix($danger, #ffff00);
+    color: var(--encrypt-warn, mix($danger, #ffff00));
     margin: 0 0 0 0.5em;
   }
 
diff --git a/plugin.rb b/plugin.rb
index d018a4c..3a73a0b 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -9,6 +9,7 @@
 enabled_site_setting :encrypt_enabled
 
 register_asset 'stylesheets/common/encrypt.scss'
+register_asset "stylesheets/colors.scss", :color_definitions
 %w[bars exchange-alt far-clipboard file-export file-import lock plus ticket-alt times trash-alt unlock wrench].each { |i| register_svg_icon(i) }
 
 Rails.configuration.filter_parameters << :encrypt_private

GitHub sha: d8758ec7