Have a look at phone-numbers-changing-to-unwanted-gray-color-on-iphone-and-ipad post.
It is possible that you have the same issue where you link color is what is determining the iOS color and you may need to setup a Browser Specific CSS plugin according to the post
Update: 9th Nov 2014
I found another post update-banning-blue-links-on-ios-devices which effected a change for a test phone link on my wordpress site.
Although the numbers where a light blue because they are being data detected.
This solution may or may not help you figure your issue.
In the post they offer various ways of achieving a change with various results.
Their favourite is the option 5.
Which is surrounding the number in a custom span class.
Declare you css classes as normal in your head:
.appleLinksWhite a {color: #ffffff !important; text-decoration: underline;}
.appleLinksBlack a {color: #000000 !important; text-decoration: none;}
.appleLinksRed a {color: #FF0000 !important; text-decoration: none;}
and the surround the number in the chosen class
contact:<span class="appleLinksRed"> 0205 992 9921</span>