https://birthwithoutfearblog.com/2013/06/06/alternative-methods-of-checking-dilation-the-purple-line-and-more/I don't necessarily know the validity of this, but my sister sent me this article and it seemed like an interesting one to share. Definitely something I'd be interested in learning how true it is.
Re: Purple Line
There is just a hint of a purplish line. I'll try to remember to check again when it's show time