Here is my tab bar:

The following image shows the program being run an
First of all, make sure you have added the BOOLEAN key "View controller-based status bar appearance" to Info.plist, and set the value to "NO".
Appdelegate.swift
Insert code somewhere after "launchOptions:[UIApplicationLaunchOptionsKey: Any]?) -> Bool {"
UITabBar.appearance().barTintColor = UIColor(red: 0.145, green: 0.592, blue: 0.804, alpha: 1.00)
OR one of the default UI colors:
UITabBar.appearance().barTintColor = UIColor.white)
The selected item
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.white], for: .selected)
The inactive items
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.black], for: .normal)
If you don´t make the icons from scratch, alternating black and white versions are relatively easy to make in Photoshop.
Adobe Photoshop (almost any version will do)
Make sure your icon image has transparent background, and the icon itself is solid black (or close).
Open the image file, save it under a different file name (e.g. exampleFilename-Inverted.png)
In the "Adjustments" submenu on the "Image" menu:
Click "Invert"
You now have a negative of your original icon.
In XCode, set one of the images as "Selected Image" under the Tab Bar Properties in your storyboard, and specify the "inactive" version under "Bar Item" image.
Ta-Da