diff --git a/theme-github-auto.css b/theme-github-auto.css
index 2d8bbf2..5280291 100644
--- a/theme-github-auto.css
+++ b/theme-github-auto.css
@@ -394,6 +394,11 @@
   .ui.basic.primary.buttons .button:hover {
     box-shadow: inset 0 0 0 0px transparent !important;
   }
+  // background color of branch name in PRs
+  .issue.list .branches .branch {
+    background-color: #afb8c133;
+    border-radius: 6px;
+  }
 }
 @media (prefers-color-scheme: dark) {
   :root {
diff --git a/theme-github.css b/theme-github.css
index 66e06e9..9a1852d 100644
--- a/theme-github.css
+++ b/theme-github.css
@@ -388,3 +388,9 @@ ui.basic.blue.button:hover,
 .ui.basic.primary.buttons .button:hover {
   box-shadow: inset 0 0 0 0px transparent !important;
 }
+
+// background color of branch name in PRs
+.issue.list .branches .branch {
+  background-color: #afb8c133;
+  border-radius: 6px;
+}