diff --git a/phpBB/styles/prosilver/theme/colours.css b/phpBB/styles/prosilver/theme/colours.css
index 10ed275a9a..46eaa999b5 100644
--- a/phpBB/styles/prosilver/theme/colours.css
+++ b/phpBB/styles/prosilver/theme/colours.css
@@ -1407,7 +1407,7 @@ li.notification-disapproved strong {
 }
 
 .badge {
-	background-color: #D31141;
+	background-color: #d31141;
 	color: #ffffff;
 }
 /* stylelint-enable */