Huzzah! Apple have released a proper solution with iOS7! As explained in this answer you can use the linkTextAttributes property of a UITextView. A white, underlined link would look something like this:
yourTextView.linkTextAttributes = @{
NSForegroundColorAttributeName: [UIColor whiteColor],
NSUnderlineStyleAttributeName: [NSNumber numberWithInt:NSUnderlineStyleSingle]
};
or alternatively you could change the tintColor, since UITextView inherits from UIView and uses the tintColor property to colour links - see:
yourTextView.tintColor = [UIColor whiteColor];
Now your links can look epic!