Liner faded right along seam

[tschutz1]

We've had our pool for 4+ years now. Something strange is happening this summer, though.

The liner is faded badly, but only right along one seam on the liner. So if it was from the sun or from dumping chlorine in, etc. I wouldn't expect it to fade perfectly right along one seam. I have to believe it has something to do with the manufacture of the liner that somehow the color is faded on that particular strip of vinyl.

Any ideas? I forgot my phone at home today or else I'd post a picture as well.

 

[zea3]

It may just be that the 2 pieces of vinyl were from different runs and one fades at a quicker pace than the other. Now that my pool is 10 years old I see areas where one section is faded more than the other as well, in fact the areas that get more sun are more faded, especially above the waterline.