diff --git a/web/styles/app_variables.css b/web/styles/app_variables.css
index 7458009b1a..ad13f73f64 100644
--- a/web/styles/app_variables.css
+++ b/web/styles/app_variables.css
@@ -194,7 +194,7 @@
     --color-background-private-message-header: hsl(46deg 35% 93%);
     --color-background-private-message-content: hsl(45deg 20% 96%);
     --color-background-stream-message-content: hsl(0deg 0% 100%);
-    --color-selected-message-outline: hsl(217deg 64% 59%);
+    --color-selected-message-outline: hsl(217deg 64% 59% / 60%);
     --color-message-list-border: hsl(0deg 0% 0% / 16%);
     --color-message-header-contents-border: hsl(0deg 0% 0% / 10%);
     --color-private-message-header-border: hsl(0deg 0% 0% / 10%);