I have Inverted Colors turned on for higher contrast, on my iPhone 6 (iOS 9). So, most of the screens are white on black. However, the Home & Lock screens have a white background. I have not figured out how to make the Home and Lock screens white on black as well. I've tried taking a picture of something white and use it as the Home/Lock screen, but when it's inverted on the Home and Lock screen, it just turns the screens into a grey color. I'd really appreciate it if anyone has any suggestions.