The Guardian has a map of the results from the AV referendum. There isn't much purple. At first, I struggled to see any at all. But it turns out 21,693 people in Oxford voted Yes (54.11% of the vote).
The list is so short, I may as well be exhaustive. Cambridge also voted Yes, with 54.32% in favour of AV. In Scotland, Glasgow Kelvin and Edinburgh Central voted Yes (58.78% and 51.36% respectively). The only other places with a Yes majority were the London boroughs of Hackney (60.68%), Islington (56.92%), Haringey (56.62%), Lambeth (54.69%), Southwark (52.73%) and Camden (51.4%).