diff --git a/public/themes/bootstrap4-dark-blue/theme.css b/public/themes/bootstrap4-dark-blue/theme.css
index 1635ef123..914e2601f 100644
--- a/public/themes/bootstrap4-dark-blue/theme.css
+++ b/public/themes/bootstrap4-dark-blue/theme.css
@@ -5396,4 +5396,8 @@
   content: "/";
 }
 
+.fc.fc-theme-standard .fc-highlight {
+  background: #476880;
+}
+
 /* Customizations to the designer theme should be defined here */
diff --git a/public/themes/bootstrap4-dark-purple/theme.css b/public/themes/bootstrap4-dark-purple/theme.css
index 73677f4c9..b3782a7ae 100644
--- a/public/themes/bootstrap4-dark-purple/theme.css
+++ b/public/themes/bootstrap4-dark-purple/theme.css
@@ -5396,4 +5396,8 @@
   content: "/";
 }
 
+.fc.fc-theme-standard .fc-highlight {
+  background: #614c6c;
+}
+
 /* Customizations to the designer theme should be defined here */
diff --git a/public/themes/bootstrap4-light-blue/theme.css b/public/themes/bootstrap4-light-blue/theme.css
index 6d7e3f718..163da8c8a 100644
--- a/public/themes/bootstrap4-light-blue/theme.css
+++ b/public/themes/bootstrap4-light-blue/theme.css
@@ -5396,4 +5396,8 @@
   content: "/";
 }
 
+.fc.fc-theme-standard .fc-highlight {
+  background: #cce5ff;
+}
+
 /* Customizations to the designer theme should be defined here */
diff --git a/public/themes/bootstrap4-light-purple/theme.css b/public/themes/bootstrap4-light-purple/theme.css
index ab6913f28..79815e710 100644
--- a/public/themes/bootstrap4-light-purple/theme.css
+++ b/public/themes/bootstrap4-light-purple/theme.css
@@ -5396,4 +5396,8 @@
   content: "/";
 }
 
+.fc.fc-theme-standard .fc-highlight {
+  background: #e7d8ef;
+}
+
 /* Customizations to the designer theme should be defined here */