Its the micro glitter that makes the clear plastic appear to be dirty. I got lucky on the tails too....every one got the stripe. If you look at the top bait facing to the right and follow its tail to the end you can see the pink stripe turn the corner and run towards the bottom of the tail button. They all do that. Its cool to see. The picture was taken under artificial lights. The sun is up now so I'm headed outside with them to see how they like natural light. lol