Hi, Is your website having default blue hyperlink colour from a telephone number when viewed on an iPhone? Sometimes if your site have telephone number on page then on iphone it shows link blue link and even after using CSS on it, it still shows blue. I also got this issue on one of my website I was working and then finally I found solution of it by Apple-Specific Meta Tag Keys.
If you want to remove this default link on telephone number on iphone then you need to use below apple specific meta tag :
<meta name="format-detection" content="telephone=no">
Put above meta tag in “<head>” tag of your webpage and then you will see that default link on telephone number will be removed.
I hope this post solve your time and issue. Let me know if you have any thoughts in comments.