I'm British of Indian parentage, just for the record before I go on.
During my 20s, became great friends with a guy who lived on my street when I bought my first flat in the East End of London. He'd lived in his house most of his adult life and was in his late 50s. The street had completely changed in his time there, had gone from being very poor/working class/rented to being filled with middle class professionals (doctors, lawyers, teachers, even a reasonably famous actor and chef). And we interlopers came in all shapes, sizes and colours. This chap loved the street, knew everyone living there and the ins and outs of their lives, was truly proud of everyone's achievements and sympathetic and helpful if you ever needed help.
He was also a former National Front member. As a poor, white, working class young man, this was a decision he had made as he saw his childhood "manor" change with the influx of immigrants in the 60s. His initial reaction to this change had been to fight against it, and join an organisation that seemed to reflect/embrace his feelings.
As he put it, he grew up. He worked with and lived next to people from a different race/culture and found no threat there. He relinquished his NF membership and moved on.
When he told me that, I could have cut him off for his former beliefs, but I think that would have been wrong and I'd have missed out on knowing a lovely man. So, in answer to your question, if that person had truly changed, yes, I'd be friends with them. I learned a lot from my friend.