Voicing a different ethnicity, OK or not?

So I am having an argument with a player, I literally have no idea if I am right or wrong on this.

I played Pathfinder Kingmaker on PC and loved Ekundayo the Ranger who was a person of colour, great NPC and great voice. I am playing Pathfinder as a player and my Character is called...Ekundayo! I created him as a homage to my favourite character but created my own backstory to fit our game. I am an escaped slave (captured at 14) from the Mwangi Expanse who became a street urchin in Sandpoint before being arrested and rather than going to prison I became a Black Arrow... Yes I am playing Rise of the Runelords and this character joins at the appropriate Black Arrow juncture (Spoilers as free as possible)

Now, Ekundayo learnt Common at 15 when he escaped so would talk, like Ekundayo in the PC game, with an accent of Mwangi Expanse which as a gaming group we agree sounds like Nigerian or Angolan. Is it wrong for me to voice him being a white guy? One of my players says it is and I have been asked to revert to my posh east London/ mildly Mancunian accent but to me that completely changes the character. "Nah mate, I was captured in the Mwangi Expanse innit" I think I am voicing a character, much like my DM/GM does when different races are encountered and am not doing a comedy voice, I am literally doing a cross between Nigerian and English. I have a muse for this too with a work colleague who is from Nigeria and mixes her accent with Mancunian and also says she can't see an issue.

Thoughts and advice please.