Keep2theCode

IMPORTANT: If you are updating this plugin from an older version, be sure to have backups of any stylesheets or icons, because you will need to re-upload them via the new form.
This plugin allows you to “tweak” or do minor overrides to the style for any theme, much like a child theme. But it also makes it easy to show images for your site’s logo, url, smartphone bookmark, and social sharing at sites such as Facebook.
For styles, first create a style sheet for the theme you want to adjust. For example, if you have a theme called soverycool, you might name your style sheet soverycool.css. Your file only needs to contain those style elements you’d like to change.
Next, upload it via the Upload File form. Once your file is uploaded, just insert its name into the css filename box and press Set Style. If you have several themes, you can keep all of your custom style sheets in that directory as long as they have different names. Then just enter the name for whichever theme you’re using at the time.
To stop using your custom style, just remove the name from the css filename box and press Set Style. You do not need to actually delete your files from the uploads directory.
For icons, upload them via the Upload File form and repeat for each icon. The names have to be favicon.ico, phone.png, share.png, and logo.png. Changing them is as easy as uploading new files with the same name. For your site logo to appear, the following code needs to be added to your theme’s header in the place you want it to appear: <code><?php thtw_logo(); ?></code>

Theme Tweak

Do minor changes to any theme styling, and easily display site images: logo, favicon, smartphone icon, and sharing icon.

Scott Reilly

Ever want to tweak the appearance of the WordPress admin pages by hiding stuff, moving stuff around, changing fonts, colors, sizes, etc? Any modification you may want to do with CSS can easily be done via this plugin.
Using this plugin you’ll easily be able to define additional CSS (inline and/or files by URL) to be added to all administration pages. Hooks are provided to customize the output of the CSS, the CSS files, and if/when the CSS should even be output (see Hooks section).
Links: <a href="https://coffee2code.com/wp-plugins/add-admin-css/" rel="nofollow ugc">Plugin Homepage</a> | <a href="https://wordpress.org/plugins/add-admin-css/" rel="ugc">Plugin Directory Page</a> | <a href="https://github.com/coffee2code/add-admin-css/" rel="nofollow ugc">GitHub</a> | <a href="https://coffee2code.com" rel="nofollow ugc">Author Homepage</a>
<h3>Developer Documentation</h3>
Developer documentation can be found in <a href="https://github.com/coffee2code/add-admin-css/blob/master/DEVELOPER-DOCS.md" rel="nofollow ugc">DEVELOPER-DOCS.md</a>. That documentation covers the hooks provided by the plugin.
As an overview, these are the hooks provided by the plugin:
<ul>
<li><code>c2c_add_admin_css</code> : Filter to customize the CSS that should be added directly to the admin page head.</li>
<li><code>c2c_add_admin_css_files</code> : Filter to customize the list of CSS files to enqueue in the admin.</li>
<li><code>c2c_add_admin_css_disable_css</code> : Filter to customize if the CSS defined via this plugin should be output or not.</li>
</ul>

Add Admin CSS

This plugin did *exactly* what I wanted. A plugin had dropped some ad stuff into the Publish box, but it had a good CSS class, so I just hid it.

I really like that the text field for holding the CSS is intelligent and does things like auto include closing brackets, code coloring, etc.

Worked perfectly

Easily define additional CSS (inline and/or by URL) to be added to all administration pages.

Theme Tweak vs Add Admin CSS