>>21453296This, although a bar here was doing mixed fries for a while. Purple fries, regular fries and pink/red fries. They were of different thicknesses/cuts and my only guess would be, after trying to fry purple potatoes at home, it was done to keep the colours. Fried properly, purple potatoes turn grey but theirs were still a vibrant violet. They were fried as matchsticks, which require only a single frying to get crisp. The regular were steak-cut and the pinks/reds were regular-cut.
If there are orange potatoes that aren't disgusting-ass sweet potatoes, mixing the two could be nice and novel.