Applied the branch CSS class at the correct level to apply to select2.

assets/css/admin.scss

@@ -6818,8 +6818,6 @@ table.bar_chart {
 /**
   * Select2 colors for built-in admin color themes.
   */
-.branch-5-3 {
-
 .admin-color {
 	$wp_admin_colors: (
 		blue: #096484,
@@ -6833,7 +6831,7 @@ table.bar_chart {
 
 	@each $name, $color in $wp_admin_colors {
 
-			&-#{$name} {
+		&-#{$name}.branch-5-3 {
 
 			.select2-dropdown {
 				border-color: $color;
@@ -6865,7 +6863,6 @@ table.bar_chart {
 		}
 	}
 }
-}
 
 
 .post-type-product .tablenav,