When I try to change the name or colour of a label I get the message: 'You already have a label with that name.' so I can't make any changes.
Using Chrome on a Mac.
Sorry for the inconvenience, we're looking into this issue now.
Just to update you, the behaviour has slightly changed now. When I go to edit a label, I still get the error message, but the label name now goes blank, and I have to re-add it, which is then accepted.
The result is that I can now edit things, but obviously something a bit strange is going on.
Indeed, this happens if you change the label's color. We're looking into it now.
This should now be fixed.