iOS 13 dark mode: UIColor.link too dark when used for NSAttributedString

Question

with iOS 13 dark mode, I use UIColor.link for two cases:

• foregroundColor color for NSAttributedString
• tint color for icons

problem: though I use UIColor.link in both cases, they render as different colors. The color rendered for NSAttributedString is darker and I find this color really hard to read over a black background.

code for NSAttributedString

if #available(iOS 13.0, *) {
    linkAttributes[.foregroundColor] = UIColor.link
} else {
    linkAttributes[.foregroundColor] = UIColor.blue
}
// .font is the only other attribute I set
let attStr = NSAttributedString(string: cardName, attributes: linkAttributes)

I use this attributed string in a UIButton subclass that I instantiate programmatically:

class ConditionButton: UIButton {
    required init() {
        super.init(frame: .zero)
        configureOnce()
    }

    func configureOnce() {
        self.titleLabel?.numberOfLines = 0
        self.titleLabel?.lineBreakMode = .byWordWrapping
        self.titleLabel?.font = labelFont
        self.contentHorizontalAlignment = .left
    }

    // some more code that does self.setAttributedTitle(attributedString, for: .normal)
}

The text at the top is a hard to read label of a subclass of UIButton with NSAttributedString , at the bottom, there is an easy to read UIButton with an image and tintColor = UIColor.link

Why is that and how can I get the same readable color for NSAttributedString ?

Answer 1

This is a combination of...

My mistake:

When I asked the question, I did not notice, that I had the following line in my code:

linkAttributes[.link] = url

I don't need this attribute any more, since I us a button now.

Bug in NSAttributedString :

When using

linkAttributes[.link] = url

in an NSAttributedString , Apple overrides the color with a dark blue that was ok until iOS 12 .

It appears, Apple has forgotten to use UIColor.link for links in NSAttributedString .

So, everybody who uses the .link attribute in dark mode will produce this unreadable dark blue color.

I'll file a radar after writing this answer.