Fix QPalette highlights not working for all macOS themes

CHANGELOG.md

@@ -65,6 +65,7 @@ The **"Breaking Changes"** listed below are changes that have been made in the d
 - Metatile behaviors with no constant will now display their value in the Tileset Editor.
 - Fix incorrect limits on Floor Number and Border Width/Height in the New Map Options window.
 - Fix Border Width/Height being set to 0 when creating a new map from an existing layout.
+- Fix certain UI elements not highlighting red on some platforms.
 
 ## [4.5.0] - 2021-12-26
 ### Added

src/editor.cpp

@@ -265,14 +265,10 @@ void Editor::addNewWildMonGroup(QWidget *window) {
     lineEdit->setValidator(validator);
     connect(lineEdit, &QLineEdit::textChanged, [this, &lineEdit, &buttonBox](QString text){
         if (this->project->encounterGroupLabels.contains(text)) {
-            QPalette palette = lineEdit->palette();
-            QColor color = Qt::red;
-            color.setAlpha(25);
-            palette.setColor(QPalette::Base, color);
-            lineEdit->setPalette(palette);
+            lineEdit->setStyleSheet("QLineEdit { background-color: rgba(255, 0, 0, 25%) }");
             buttonBox.button(QDialogButtonBox::Ok)->setDisabled(true);
         } else {
-            lineEdit->setPalette(QPalette());
+            lineEdit->setStyleSheet("");
             buttonBox.button(QDialogButtonBox::Ok)->setEnabled(true);
         }
     });

src/mainwindow.cpp

@@ -2590,9 +2590,7 @@ void MainWindow::on_pushButton_ChangeDimensions_clicked()
     }
 
     QLabel *errorLabel = new QLabel();
-    QPalette errorPalette;
-    errorPalette.setColor(QPalette::WindowText, Qt::red);
-    errorLabel->setPalette(errorPalette);
+    errorLabel->setStyleSheet("QLabel { color: red }");
     errorLabel->setVisible(false);
 
     QDialogButtonBox buttonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, Qt::Horizontal, &dialog);

src/ui/newmappopup.cpp

@@ -6,7 +6,6 @@
 
 #include <QMap>
 #include <QSet>
-#include <QPalette>
 #include <QStringList>
 
 struct NewMapPopup::Settings NewMapPopup::settings = {};
@@ -228,13 +227,9 @@ void NewMapPopup::useLayout(QString layoutId) {
 
 void NewMapPopup::on_lineEdit_NewMap_Name_textChanged(const QString &text) {
     if (project->mapNames.contains(text)) {
-        QPalette palette = this->ui->lineEdit_NewMap_Name->palette();
-        QColor color = Qt::red;
-        color.setAlpha(25);
-        palette.setColor(QPalette::Base, color);
-        this->ui->lineEdit_NewMap_Name->setPalette(palette);
+        this->ui->lineEdit_NewMap_Name->setStyleSheet("QLineEdit { background-color: rgba(255, 0, 0, 25%) }");
     } else {
-        this->ui->lineEdit_NewMap_Name->setPalette(QPalette());
+        this->ui->lineEdit_NewMap_Name->setStyleSheet("");
     }
 }