iOS13 UIAlertController with custom view & preferredStyle as actionsheet grayscale all colours

I'm not exactly sure if it's a bug or a feature, but this code:

let sheet = UIAlertController(customView: awesomeView, preferredStyle: .actionSheet)
....
present(sheet, animated: true, completion: nil)

in pre-iOS 13 gives me this result:

https://i.stack.imgur.com/nh8tf.png

and on iOS 13:

https://i.stack.imgur.com/l9fVb.png

w/o any code-changes. I.e. all the customview's elements have been grayscale.

How can I avoid that?

Also, I've noticed that if I change the preferredStyle to

.alert

.actionSheet

OS: iOS 13 & Xcode 11 - beta 3 (also had exactly the same problem with beta 1 and 2)

Or does it mean that I'm no longer expected to use UIAlertController?