Some of the Syrians shown on T.V including their president look quite white enough.So one can safely assume that during the Slavic slave trade,white genes did indeed mix a lot along with those of the white Roman converts in Arabs even though those with their original features are also seen in that part of the world.
Indeed, the Crimean Khanate exported hundreds of thousands Slavic slaves to the Ottoman empire and Egypt over the centuries and keeping a slave population of approximately 120.000 on the Krim itself. In the last two centuries the Ottomans rulers moved many Caucasian or adjacent groups to Syria.