I just received an official response from Apple. They say that this is the intended behaviour. That's weird.
However, I still think it's a iOS 13 bug because if you assign an image (setIncrementImage or setDecrementImage) the component start to correctly respond to tintColor. You can even set it's default image!
So, in conclusion, if you want to change the tint color of a UIStepper in iOS13 you need to add these two lines of code:
stepper.setDecrementImage(stepper.decrementImage(for: .normal), for: .normal) stepper.setIncrementImage(stepper.incrementImage(for: .normal), for: .normal)
I reported this just today. I don't see how this can be behaving correctly since it no longer uses the tint color for the border like it used to.
Yeah. Thats a bug regardless of what they say. it is nonsensical to set the image to the one it already has as a practice. I submitted a bug for it referencing this thread.
Thanks @DaleOne for finding a way to make it work.