Change the color of a link in an NSMutableAttributedString

I have the following code but my links are always blue. How do I cange the color of them?

[_string addAttribute:NSLinkAttributeName value:tag range:NSMakeRange(position, length)];
[_string addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue-Bold" size:(12.0)] range:NSMakeRange(position, length)];
[_string addAttribute:NSStrokeColorAttributeName value:[UIColor greenColor] range:NSMakeRange(position, length)];

_string is a NSMutableAttributedString and the position and length work fine.

Swift

Updated for Swift 4.2

Use linkTextAttributes with a UITextView

textView.linkTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.green]

And in context:

let attributedString = NSMutableAttributedString(string: "The site is www.google.com.")
let linkRange = (attributedString.string as NSString).range(of: "www.google.com")
attributedString.addAttribute(NSAttributedString.Key.link, value: "https://www.google.com", range: linkRange)
let linkAttributes: [NSAttributedString.Key : Any] = [
    NSAttributedString.Key.foregroundColor: UIColor.green,
    NSAttributedString.Key.underlineColor: UIColor.lightGray,
    NSAttributedString.Key.underlineStyle: NSUnderlineStyle.single.rawValue
]

// textView is a UITextView
textView.linkTextAttributes = linkAttributes
textView.attributedText = attributedString

Objective-C

Use linkTextAttributes with a UITextView

textView.linkTextAttributes = @{NSForegroundColorAttributeName:[UIColor greenColor]};

Source: this answer

And from this post:

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"This is an example by @marcelofabri_"];
[attributedString addAttribute:NSLinkAttributeName
                         value:@"username://marcelofabri_"
                         range:[[attributedString string] rangeOfString:@"@marcelofabri_"]];


NSDictionary *linkAttributes = @{NSForegroundColorAttributeName: [UIColor greenColor],
                                 NSUnderlineColorAttributeName: [UIColor lightGrayColor],
                                 NSUnderlineStyleAttributeName: @(NSUnderlineStyleSingle)};

// assume that textView is a UITextView previously created (either by code or Interface Builder)
textView.linkTextAttributes = linkAttributes; // customizes the appearance of links
textView.attributedText = attributedString;
textView.delegate = self;

The link color is the tint color of the label/textView. So, you can change it by changing the tint color of the view. However, this will not work if you want different link colours within the same view.