UITabBarAppearanceExample.swift

let appearance = UITabBarAppearance()
appearance.configureWithTransparentBackground()
appearance.backgroundColor = backgroundColor
appearance.backgroundImage = backgroundImage

[appearance.stackedLayoutAppearance,
 appearance.compactInlineLayoutAppearance,
 appearance.inlineLayoutAppearance]
    .forEach {
        $0.selected.iconColor = selectedColor
        $0.selected.titleTextAttributes[.foregroundColor] = selectedColor
        $0.normal.iconColor = unselectedColor
        $0.normal.titleTextAttributes[.foregroundColor] = unselectedColor
        // Tab bar title text workaround
        // https://stackoverflow.com/questions/58641202/ios-tabbar-item-title-issue-in-ios13
        if let font = $0.normal.titleTextAttributes[.font] as? UIFont {
            $0.normal.titleTextAttributes[.font] = UIFont.systemFont(ofSize: font.pointSize)
        }
    }

tabBar.standardAppearance = appearance
tabBar.scrollEdgeAppearance = appearance