delwinv

A very tiny plugin that adds the ACF field key, field name, Flexible Content field name and Flexible Content layout name to the WYSIWYG 
editor body tag, allowing you to target these classes, along with the existing post-type-* classes added by default by WordPress, in 
your editor-style.css for a better admin/editor experience.
This works for both ACF and ACF Pro, version 5.
<h3>Usage</h3>
<ol>
<li>Install the plugin through the Install Plugins interface or by uploading the <code>acf-plugin-wysiwyg-styling</code> folder to your <code>/wp-content/plugins/</code> directory.</li>
<li>Activate the ACF WYSIWYG Styling plugin from the Admin > Plugins menu.</li>
<li>Create or edit your editor-style.css in your theme directory and use the newly added classes to style your WYSIWYG editors.</li>
</ol>
For example:
<ul>
<li>
The ACF WYSIWYG field with key field_9999ffff11112222 can be targeted with the following CSS:
body.acf-field-key-field_9999ffff11112222 { 
 background-color: red; 
}
</li>
<li>
The ACF WYSIWYG field with key field_9999ffff11112222 in the “room” post type can be targeted with the following CSS:
body.post-type-room.acf-field-key-field_9999ffff11112222 { 
 background-color: blue; 
}
</li>
<li>
All ACF WYSIWYG fields named “my_wysiwyg” can be targetted with the following CSS:
body.acf-field-name-my_wysiwyg { 
 background-color: yellow; 
}
</li>
<li>
All ACF WYSIWYG fields in the Flexible Content field named “page_content” can be targetted with the following CSS:
body.acf-flex-name-page_content { 
 color: green; 
}
</li>
<li>
All ACF WYSIWYG fields in the Flexible Content layout field named “test_layout” can be targetted with the following CSS:
body.acf-layout-test_layout { 
 font-family: “Computer Modern Serif”; 
}
</li>
<li>
The ACF WYSIWYG field named “my_wysiwyg” in the Flexible Content layout field named “test_layout” can be targetted with the following CSS:
body.acf-layout-test_layout.acf-field-name-my_wysiwyg { 
 border: 4px solid red; 
 height: 100%; 
 margin: 0 auto; 
 max-width: 100px; 
}
</li>
</ul>
N.B. I target using the body tag so that a user cannot accidentally target the admin CSS in their edit of the field (regardless of how unlikely 
that would be).

ACF WYSIWYG Styling

Provides the necessary CSS classes in ACF WYSYWIG editor to allow for complete styling of the admin interface.

emrysh

Half Baked Category Colours adds a per-category colour picker and applies those colours sitewide wherever categories are displayed.
It is designed to be simple in day-to-day use. Set a colour once on the category screen and you are done. If you want a consistent “category pill” look across themes, you can optionally enable pill styling and fine-tune spacing, tint, underline, border thickness, and pill shape.
Highlights 
* Set a colour per category on Posts → Categories (add or edit), plus Quick Edit support. 
* Optional default category colour (used when a category has no specific colour). 
* Optional pill styling (rounded borders + padding), plus controls for pill gap, border thickness, pill shape, background tint, and underline. 
* Category list screen improvements, including a colour swatch column and Quick Edit colour picker. 
* Optional category name case tools (categories only), including Storage case, auto-apply on create or edit, forced Display case, and Normalize all.
<h4>How it works</h4>
<ol>
<li>Go to Posts → Categories and set a colour for each category you want styled.</li>
<li>Optionally set a Default category colour to cover anything left unset.</li>
<li>Optionally enable pill styling for a consistent look across themes.</li>
</ol>
<h4>Inheritance</h4>
If a child category has no colour set, it can inherit its parent category colour.
<h4>Privacy and data</h4>
This plugin does not send any data off-site. Colours and settings are stored locally in your WordPress database.
<h4>Uninstall</h4>
Uninstalling the plugin removes plugin settings and any stored metadata created by the plugin.

Half Baked Category Colours

Add a per-category colour picker and apply category colours sitewide, with optional pill styling and category case tools.

ACF WYSIWYG Styling vs Half Baked Category Colours