Images are not displayed in contrast mode

In high contrast mode, background images are eliminated. If your slider is loading images as background images in CSS, they’ll automatically be eliminated.

You can override this by creating a custom high-contrast CSS stylesheet. Copy the file ‘a11y-contrast.css’ that’s in the WP Accessibility directory at wp-accessibility/toolbar/css/a11y-contrast.css and place it in your theme’s directory. Edit it to prevent the background images from being overridden in the contexts where you need them to stay. I can’t be more specific, I’m afraid.