I will immediately confess - I am not a vegan... not even a vegetarian, but this food-advice is applicable even to vegans (I enjoyed the dish with a can of sardines).
It is about colour in food.
If you take one part chopped kale, one part chopped red cabbage and one part potatoes, and boil it together to a sort of mash (the seasoning is secret), the mixing of the bluish violet of the red Cabbage and the green of the kale will make what is best described as a dirty purple. To this the potatoes add a matt and gritty texture... Looking like this:
It was actually not unpleasant - fine taste - but my youngest daughter had to leave the room.