How can I change the UISearchBar search text color?

You have to access the UITextField inside the UISearchBar. You can do that by using valueForKey("searchField")

var textFieldInsideSearchBar = yourSearchbar.valueForKey("searchField") as? UITextField

textFieldInsideSearchBar?.textColor = yourcolor

Swift 3 update

let textFieldInsideSearchBar = yourSearchbar.value(forKey: "searchField") as? UITextField

textFieldInsideSearchBar?.textColor = yourcolor

If you want to set text color for UISearchBar in storyboard (without code), it is easy to do as well (in identity inspector). Here is a red text for search bar.

If you only need to make it readable on a dark background you can change the barStyle. The following makes text and buttons in the searchbar white:

searchController.searchBar.barStyle = .black

Working in Swift 4 for me:

UITextField.appearance(whenContainedInInstancesOf: [UISearchBar.self]).defaultTextAttributes = [NSAttributedStringKey.foregroundColor.rawValue: UIColor.white]

Swift 4.2, IOS 12:

UITextField.appearance(whenContainedInInstancesOf: [UISearchBar.self]).defaultTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]

public extension UISearchBar {

    public func setTextColor(color: UIColor) {
        let svs = subviews.flatMap { $0.subviews }
        guard let tf = (svs.filter { $0 is UITextField }).first as? UITextField else { return }
        tf.textColor = color
    }
}