No, they're all carrion crows – the 'regular' kind of crow. The fledgling crows take a while to get their dark black sheen, plus I've noticed quite a bit of albinism in the Peckham Rye crow population. There are several with a number of white and grey feathers.
Someone I know has made a short film about these crows as they're a fascinating example of a species changing its behaviour relatively quickly in the face of changes in the environment. Traditionally in the countryside, carrion crows were relatively solitary birds, whereas rooks were the highly sociable kind. But as crows have moved into towns and cities, they've become more sociable (probably a good strategy for finding food and finding a mate) and have developed social hierarchies. This is just within the last twenty years or so, which is remarkably rapid. But crows, as has been said, are amazingly good learners and experimenters, so they've found a niche quickly and successfully.
As you can probably tell, I love 'em