Open Radar

 
Summary:
We can now set the tint colour of the navigation bar on SFSafariViewController which means we are also more likely to set the tint colour on the view property of SFSafariViewController to affect the colour of the buttons (Done, back, forward etc). In our app we have the preferred tint colour set to red and the view tint colour to white. (See attached screenshot for result). This looks great until the user chooses the action button which presents a UIActivityViewController which then has a white cancel button.

There appears to be no way to set the tint colour of this presented view separately.

Steps to Reproduce:
1. Implement the following code
```
                SFSafariViewControllerConfiguration *config = [SFSafariViewControllerConfiguration new];
                config.preferredBarTintColor = [UIColor redColor];
                SFSafariViewController *safariViewController = [[SFSafariViewController alloc] initWithURL:url configuration:config];
                safariViewController.view.tintColor = [UIColor whiteColor];

                [self presentViewController:safariViewController animated:true completion:nil];

```
2. Activate the code to push a website
3. Observe that bars are red and buttons are white
4. Choose the action button in the toolbar
5. See that cancel button text is white and therefore invisible

Expected Results:
I expect to be able to configure the tint colour of the activity view

Actual Results:
There is no way to configure the colour. The text is white and not visible to the user.

Regression:
Only occurs due to tint colour being set to white which I believe is a valid use case.

Notes:
Have been unable to find a workaround