Fix keyboard selection styles for errored form dropdown

src/definitions/collections/form.less

@@ -474,6 +474,14 @@
 .ui.form .field.error .ui.dropdown .menu .item:hover {
   background-color: @dropdownErrorHoverBackground;
 }
+
+/* Selected */
+.ui.form .fields.error .field .ui.dropdown .menu .selected.item,
+.ui.form .field.error .ui.dropdown .menu .selected.item {
+  background-color: @dropdownErrorSelectedBackground;
+}
+
+
 /* Active */
 .ui.form .fields.error .field .ui.dropdown .menu .active.item,
 .ui.form .field.error .ui.dropdown .menu .active.item {

src/themes/default/collections/form.variables

@@ -109,6 +109,7 @@
 
 /* Dropdown Error */
 @dropdownErrorHoverBackground: #FBE7E7;
+@dropdownErrorSelectedBackground: @dropdownErrorHoverBackground;
 @dropdownErrorActiveBackground: #FDCFCF;
 @dropdownErrorLabelBackground: #EACBCB;
 @dropdownErrorLabelColor: @errorTextColor;