Also, my first name and surname are from different European countries, both very very white countries - say for argument's sake it's Ulrika Roux. Neither would be common names among black or ethnic minority people. I grew up in a house with white grandparents from yet another European country, who didn't speak English, and that no doubt had a big influence on my speech. My dad is black but I never had any contact with him or his black family, so they had no influence on the way I speak.
So I have spoken to people on the phone, told them my full name, and then when I met them in person they would say "Oh, I thought you were white". Sometimes they just say this with mild curiosity or surprise, which to be honest doesn't bother me as I am fascinated by language and get where they are coming from. Other times, it's with evident disappointment, which is far more bothersome.
I was completely ridiculed in an English class at school once because I struggled to read out a poem that was written in Patois about mixed raced people (John Agard - Half Caste, if you want to look it up). The assumption was that I was a mixed raced person therefore I should be the one to read this poem. I was really reluctant at first because I could read the words on the page and knew they were supposed to be Patois, but I had absolutely no familiarity with that at all, and I am a terrible actress, I can't do other accents to save my life. I was goaded so I read it out eventually, but not in the comedy Jamaican accent that everyone expected me to be able to put on at the drop of a hat, I read it in my South London, brought up by Mediterranean grandparents accent. Which should be fine, but the black girls in the class laughed at me/scolded me for rejecting my black identity, and the white teacher was annoyed at me for not playing ball and being stubborn and making a fuss. Which, ironically, was completely proving the point the poet was making.
So people do assume links between ethnicity and language, sometimes pejoratively.