fiskeben

This plugin adds a simple way to let your readers enable or disable a high contrast stylesheet for the visually impaired.
Once a reader enables the high contrast stylesheet the setting will be stored in a cookie which means the setting will not only stay one when navigating to other pages but it will also be on when the reader returns.

Vividly

Enables toggling an extra stylesheet with high contrast CSS for visually impaired users.

mediarlos

Simple Accessibility Tools adds a configurable accessibility toolbar to public WordPress pages to improve reading comfort and navigation.
Included features:
<ul>
<li>Increase and decrease font size.</li>
<li>High contrast mode.</li>
<li>Visual filters: normal, sepia, inverted, negative, and grayscale.</li>
<li>Reading line that follows the cursor.</li>
<li>Increased text, word, and line spacing.</li>
<li>Readable font mode.</li>
<li>Link highlighting.</li>
<li>Pause animations.</li>
<li>Hide images, videos, and iframes.</li>
<li>Large cursor mode.</li>
<li>Reset visitor preferences.</li>
<li>Visitor preference persistence with localStorage.</li>
<li>Admin settings panel with checkboxes to enable or disabPlugin Checkle each option.</li>
<li>Language selector: Spanish, English, and French. English is the default language.</li>
<li>“Buy me a coffee” support link inside the admin settings panel.</li>
</ul>
When activated, the plugin inserts the toolbar on the frontend using <code>wp_footer</code>. Visible options and language are managed from Settings > Simple Accessibility Tools.

Simple Accessibility Tools

Adds a floating accessibility toolbar to the WordPress frontend.

Vividly vs Simple Accessibility Tools