Qt5中是[static] QRgb QColorDialog::getRgba(QRgb initial = 0xffffffff, bool *ok = nullptr, QWidget *parent = nullptr)

而Qt6更加直接了，[static] QColor QColorDialog::getColor(const QColor &initial = Qt::white, QWidget *parent = nullptr, const QString &title = QString(), ColorDialogOptions options = ColorDialogOptions())

返回的直接就是QColor，而不是QRgba了。