curio bluberry gin
It seems Curio have taken a slightly different approach in creating this gin. Whereas with their vodkas they impart flavour with a maceration just prior to their well known fourth distillation, it seems that in the case of this gin the blueberries are macerated in the spirit after the final distillation. This would at least explain the colour.
The blueberries are provided by Bonallack, a former monastery just a few miles from the distillery in Cornwall in an ancient cultivation site.