Change defualt theme to midnight blue colorful

Change default theme to midnight blue colorful so new user not need to see white theme

src/yuzu/configuration/config.cpp

@@ -743,7 +743,7 @@ void Config::ReadUIValues() {
     qt_config->beginGroup(QStringLiteral("UI"));
 
     UISettings::values.theme =
-        ReadSetting(QStringLiteral("theme"), QString::fromUtf8(UISettings::themes[0].second))
+        ReadSetting(QStringLiteral("theme"), QString::fromUtf8(UISettings::themes[5].second))
             .toString();
     ReadBasicSetting(UISettings::values.enable_discord_presence);
     ReadBasicSetting(UISettings::values.select_user_on_boot);