I just noticed this yesterday when I bought a bunch to customize. I had no idea the early releases I had purchased had darker pink hair! Someone must have realized the factory had the wrong pink and switched it for later batches. So far I've only seen the lighter haired one in singles that come with her bunny, not sure if the sets have changed, but all the ones I had, even the scooter pony were all darker. Luckily I saved one of the lighter ones from being customized to join my herd:)