6 files changed, 15 insertions, 11 deletions
diff --git a/launcher/ui/themes/ITheme.cpp b/launcher/ui/themes/ITheme.cpp
index 22043e44..8f0757e1 100644
--- a/launcher/ui/themes/ITheme.cpp
+++ b/launcher/ui/themes/ITheme.cpp
@@ -38,7 +38,7 @@
 #include <QDir>
 #include "Application.h"
 
-void ITheme::apply()
+void ITheme::apply(bool)
 {
     APPLICATION->setStyleSheet(QString());
     QApplication::setStyle(QStyleFactory::create(qtTheme()));
diff --git a/launcher/ui/themes/ITheme.h b/launcher/ui/themes/ITheme.h
index 2e5b7f25..a0a638bd 100644
--- a/launcher/ui/themes/ITheme.h
+++ b/launcher/ui/themes/ITheme.h
@@ -41,7 +41,7 @@ class QStyle;
 class ITheme {
    public:
     virtual ~ITheme() {}
-    virtual void apply();
+    virtual void apply(bool initial);
     virtual QString id() = 0;
     virtual QString name() = 0;
     virtual bool hasStyleSheet() = 0;
diff --git a/launcher/ui/themes/SystemTheme.cpp b/launcher/ui/themes/SystemTheme.cpp
index 24875e33..a95bc875 100644
--- a/launcher/ui/themes/SystemTheme.cpp
+++ b/launcher/ui/themes/SystemTheme.cpp
@@ -60,9 +60,13 @@ SystemTheme::SystemTheme()
     themeDebugLog() << "System theme not found, defaulted to Fusion";
 }
 
-void SystemTheme::apply()
+void SystemTheme::apply(bool initial)
 {
-    ITheme::apply();
+    // See https://github.com/MultiMC/Launcher/issues/1790
+    // or https://github.com/PrismLauncher/PrismLauncher/issues/490
+    if (initial)
+        return; 
+    ITheme::apply(initial);
 }
 
 QString SystemTheme::id()
diff --git a/launcher/ui/themes/SystemTheme.h b/launcher/ui/themes/SystemTheme.h
index b5c03def..05f31233 100644
--- a/launcher/ui/themes/SystemTheme.h
+++ b/launcher/ui/themes/SystemTheme.h
@@ -40,7 +40,7 @@ class SystemTheme : public ITheme {
    public:
     SystemTheme();
     virtual ~SystemTheme() {}
-    void apply() override;
+    void apply(bool initial) override;
 
     QString id() override;
     QString name() override;
diff --git a/launcher/ui/themes/ThemeManager.cpp b/launcher/ui/themes/ThemeManager.cpp
index 13406485..94ac8a24 100644
--- a/launcher/ui/themes/ThemeManager.cpp
+++ b/launcher/ui/themes/ThemeManager.cpp
@@ -116,22 +116,22 @@ void ThemeManager::setIconTheme(const QString& name)
     QIcon::setThemeName(name);
 }
 
-void ThemeManager::applyCurrentlySelectedTheme()
+void ThemeManager::applyCurrentlySelectedTheme(bool initial)
 {
     setIconTheme(APPLICATION->settings()->get("IconTheme").toString());
     themeDebugLog() << "<> Icon theme set.";
-    setApplicationTheme(APPLICATION->settings()->get("ApplicationTheme").toString());
+    setApplicationTheme(APPLICATION->settings()->get("ApplicationTheme").toString(), initial);
     themeDebugLog() << "<> Application theme set.";
 }
 
-void ThemeManager::setApplicationTheme(const QString& name)
+void ThemeManager::setApplicationTheme(const QString& name, bool initial)
 {
     auto systemPalette = qApp->palette();
     auto themeIter = m_themes.find(name);
     if (themeIter != m_themes.end()) {
         auto& theme = themeIter->second;
         themeDebugLog() << "applying theme" << theme->name();
-        theme->apply();
+        theme->apply(initial);
     } else {
         themeWarningLog() << "Tried to set invalid theme:" << name;
     }
diff --git a/launcher/ui/themes/ThemeManager.h b/launcher/ui/themes/ThemeManager.h
index 9af44b5a..87f36d9c 100644
--- a/launcher/ui/themes/ThemeManager.h
+++ b/launcher/ui/themes/ThemeManager.h
@@ -37,8 +37,8 @@ class ThemeManager {
 
     QList<ITheme*> getValidApplicationThemes();
     void setIconTheme(const QString& name);
-    void applyCurrentlySelectedTheme();
-    void setApplicationTheme(const QString& name);
+    void applyCurrentlySelectedTheme(bool initial = false);
+    void setApplicationTheme(const QString& name, bool initial = false);
 
     /// <summary>
     /// Returns the cat based on selected cat and with events (Birthday, XMas, etc.)