Honestly if Ursula K Leguin can write the fantasy series Earthsea with like 2 White characters in total in the 1960s, if Tolkien can write about Brown Hobbits & Elves & North African coded Dunedain in the 1930s, if Jane Austen can write about a Black heiress in Regency England, if William Shakespeare can write a play about a Black man as its main character in Tudor England, if a 13th century Medieval Author of Morien can write about a Black Knight of the round table of Arthurian legend.... then you have no excuse tbh. "It's not realistic" isn't a real excuse.
When your son has to dress up as the most obscure effin character in the DC universe, so naturally you have to dress up as a related character for context.
I'm assuming this is for a comic convention of sorts.