diff --git a/arduino-ide-extension/src/browser/style/list-widget.css b/arduino-ide-extension/src/browser/style/list-widget.css
index 3f8d44b5..b36ac409 100644
--- a/arduino-ide-extension/src/browser/style/list-widget.css
+++ b/arduino-ide-extension/src/browser/style/list-widget.css
@@ -9,7 +9,6 @@
 
 .arduino-list-widget .search-bar {
     margin: 0px 10px 10px 15px;
-    border-color: var(--theia-border-color3);
 }
 
 .arduino-list-widget .search-filters {
diff --git a/arduino-ide-extension/src/browser/style/monitor.css b/arduino-ide-extension/src/browser/style/monitor.css
index 2ad7e17a..0b32103b 100644
--- a/arduino-ide-extension/src/browser/style/monitor.css
+++ b/arduino-ide-extension/src/browser/style/monitor.css
@@ -85,8 +85,8 @@
     background: var(--theia-layout-color2);
 }
 
-.sms__control:hover {
-    border-color: var(--theia-accent-color3) !important;
+.serial-monitor-select .sms__control:hover {
+    border: var(--theia-layout-color2) var(--theia-border-width) solid !important;
 }
 
 .serial-monitor-select .sms__control--is-focused {
@@ -106,11 +106,9 @@
 }
 
 .serial-monitor-select .sms__menu {
-    background-color: var(--theia-layout-color1);
-    border: 1px solid var(--theia-layout-color2);
-    border-color: var(--theia-accent-color3);
+    background-color: var(--theia-layout-color2);
+    border: 1px solid var(--theia-accent-color3);
     top: auto !important; /* to align the top of the menu with the bottom of the control */
-    /* border-top: none; */
     box-shadow: none;
 }