pink sheep are supposed to be really rare but in my hardcore world sheep have a 1 in 10 chance or so to be pink. if you create a world on 1.9, trade with villagers to get eye of ender, get diamond gear then upgrade to 1.14 and get fire prot, blast prot, projectile prot, and prot along with mending then upgrade to 26.2 pink sheep become really common. after an hour of playing all the sheep stopped spawning and pigs spawn rate raised.
Please provide detailed reproduction steps which can be followed in a reasonable amount of time (i.e. a few minutes at most, as opposed to the length of a full survival playthrough). This report will be automatically reopened when you reply.