Updated
Display Accommodations
iOS lets you invert colors, reduce white point, enable grayscale, or choose from a range of color filters to support different forms of color blindness or other vision challenges. You can select a common preset or fine-tune the color tint and hue to customize a display setting that works for you. With the Smart Invert Colors setting, iOS automatically recognizes when a piece of media is using a dark color style, so you can reverse the colors of the display without affecting the look of images, videos, and certain apps. And once you set your filters, the settings apply to everything that appears on your iPhone.
Font Adjustments
When you activate Larger Dynamic Type, the text inside a range of apps, including Calendar, Contacts, Mail, Messages, Music, Notes, and Settings, and even some third‑party apps, is converted to a larger, easier‑to‑read size. And you can choose bold text to make the text heavier across a range of built‑in applications.