Honestly, there are not that many folktales about the color pink. One of the more entertaining ones I found is aptly titled Pink, and is a folktale (or more of an urban legend) from Florida. The story tells us about a woman who loves gardening and the color pink, and plants the entire garden full of pink flowers. The husband, feeling his masculinity threatened by the onslaught of pink, takes offense at her hobby, but despite repeated warnings, she keeps on gardening in pink. Eventually she even takes on a young man to help her with the garden chores. The husband, suspecting that the young gardener is cultivating more than just flowers, accuses her of cheating, and in a rage of passion he accidentally kills her. Scared at his crime, he buries the body under a bunch of pink flowers in the garden, and skips town. A few years later he returns, just to find out that the new owners of the house found the body and buried her in the local cemetery. Visiting the grave he finds it covered in pink flowers; the stress is too much for him, and he collapses dead. Legend says the grave is still there, completely covered in pink, except for the man-shaped empty space in the middle.
This story, apart from the entertaining use of the color pink, has a lot in common with the Lilac story I recounted earlier, and also a classic Grimm tale known as the Juniper Tree. The tale type is 720, cheerfully referred to as Mother Killed Me, Father Ate Me. It usually revolves around an unpunished murder within the family, and the soul of the dead returning in the shape of a plant or a bird to warn people of the injustice that happened to them.
I find it all kinds of fascinating that such an old story type (it exists in Greek mythology) is still alive and well, and was transplanted to the US as an urban legend.
For more pink, check out Andrew Lang's classic Pink Fairy Book.