I played around with "racebending" with the Penny Dreadful casting on Tumblr, and here's the compilation of all the doodles I made. Since 1891 was the "Golden Era" of the British Empire they really could have had it all! I did my best to pick historically accurate ethnic groups and/or nationalities. I won't make a wall of text explaining everything though!
Ethan Chandler : Native american (Lakota?)
WHY. WHY NOT. COME ON YOU HAD A NATIVE AMERICAN ACTOR RIGHT THERE. (can't find his name in casting lists ???)
Victor Frankenstein: Hong-Konger
The area was growing fast after becoming a british territory and there are some details of its early history related to massive arsenic poisoning and opium traffic that might have influenced his character in his young years. Also he could be an opium addict himself.
Caliban: West-african (Gold Coast/actual Ghana)
Who knows what this poor soul's been through before ending in Frankestein's laboratory. :T I added a lot more scars and white hair due to the said scars.
Sir Malcolm Murray : Indian
Probably a (former) Rajah (still dressing like one), torn between a certain sense of national pride and his bonds with the western world that hypocritically granted him security and wealth.
Vanessa Ives - Armenian
I tried to mix Victorian clothing with more traditional elements, such as the jewels and the two curled locks, which appear to be a common hairstyle for Armenian women around that time. Since most Armenians are Christian, it remains coherent with the whole possession thing going on. And geographically speaking, slightly closer to the whole Egyptian thing also going on. The Ottoman empire was still controlling most the area around 1891. This was just before the Armenian genocide, yes.
Brona Croft - Creole from the West Indies (Jamaica?). It's not hard to imagine all the misfortunes that could plague a lovely mixed girl travelling alone to a cold-ass country at that time, right ?
Dorian Gray - Iranian
For the record, at that time Iran was beginning to open to the western world, with a Shah who was obsessed with the art of photography, but at the same time many things (such as tobacco) were established as haram. The whole concept of the “painted portrait holding sins” could be pretty interesting from a muslim point of view!