Thankfully these particular yellow lines never fade...partly because any intelligent person would keep such a device well away from any type of moisture.

I saw something very similar to this while digging through the archives on an old ABDL site, I could resist reproducing it for myself. A friend and I each made some alterations to the original Abena design, it's not as sharp as it could be but is still well suited to something like a phone skin (sticker).

There's a version with quad-stripes on one side only and one with them on both sides. People are free to use them as they see fit, we're not exactly the owners of the base design anyway.