It's very easy to see from this image why the dubbed Uldor 'The Accursed' for not only did he gift Morgoth renewed dominion over Beleriand by the act of treachery that upset the balance of Tears Unnumbered, but this image also implies that he went against the wishes of his own heart to honour his obligations to Morgoth, faithlesss and accursed - for which he has my pity, but not my sympathy.
I tend to imagine them as quasi central asian - that's a fairly broad category. This, for example, should be Turkic/Mongolic inspired, with a fair infusion of mid-Eastern features and elements. To me, that's Asian enough - but maybe he comes across as rather Arabic/Semitic looking. It's the nose, I guess.