can't drag application/x-color from one Qt application to another (is it hex or raw?)

QVariant QInternalMimeData::retrieveData(const QString &mimeType, QMetaType type) const
{
...
    } else if (mimeType == "application/x-color"_L1 && data.metaType().id() == QMetaType::QByteArray) {
        QColor c;
        QByteArray ba = data.toByteArray();
        if (ba.size() == 8) {
            ushort * colBuf = (ushort *)ba.data();
            c.setRgbF(qreal(colBuf[0]) / qreal(0xFFFF),
                      qreal(colBuf[1]) / qreal(0xFFFF),
                      qreal(colBuf[2]) / qreal(0xFFFF),
                      qreal(colBuf[3]) / qreal(0xFFFF));
            data = c;
        } else {
            qWarning("Qt: Invalid color format");
        }

    } else if (typeId == QMetaType::QByteArray) {

        // try to convert to bytearray
        switch (data.metaType().id()) {
        case QMetaType::QByteArray:
        case QMetaType::QColor:
qDebug() << "color -> BA" << data << data.toByteArray();
            return data.toByteArray();