Change UILabel's textColor in whole app using Swift

Question

Is there any way in Swift i can change my UILabel's text color property at once in whole app? I've tried using appeareance property but that doesn't work for UILabel textColor. Any way or any library that works on the same.

Answer 1

I really liked Arash Etemad's solution, but found it quite extreme as it overrode ALL colours, even if some of them were customised. That's not great when working on an existing large project.

So I came up with this (Swift 5.2):

extension UILabel {

    override open func willMove(toSuperview newSuperview: UIView?) {
        super.willMove(toSuperview: newSuperview)

        guard newSuperview != nil else {
            return
        }

        if #available(iOS 13.0, *) {
            if textColor == UIColor.label {
                textColor = .red
            }
        } else if textColor == UIColor.darkText {
            textColor = .red
        }
    }    
}

It uses the labels own lifecycle event to override default system font colour. With the appearance of dark mode in iOS 13, that can be identified as UIColor.label, whereas before it's UIColor.darkText.

This prevents a custom font colour from being overriden (unless your custom colour is the same as the default ?!? ), whilst not requiring to manually set font colour all over the project.