If আপনি put খাবার colouring in a potato seed will the potato grow purple?

that would be awesome

no it might turn blue আপনি didnt say purple খাবার die so it might be পরাকাষ্ঠা অথবা green i think আপনি know what i mean

No, if you're only working with the seeds আপনি would have to change the potatoes' genes.
But আপনি might get some effect if আপনি constantly water the plant with heavily dyed water.(or আপনি can দ্বারা potatos that are already purple)