FuzzGuard

Want to style your Admin login pages for your clients in their corporate colors? Sick of the default wordpress wp-admin login page? Then this plugin maybe for you. It allows you to style the WordPress Admin Panel login page that comes default with every wordpress installation.
You can do the following:
<pre><code>* Upload and set your own logo for the Admin Panel login page
* Upload and set your own logo for the Admin Panel Menu (This replaces the DASHBOARD menu option)
* Set the background color of the Admin Panel login page
 * Set the background colour of the Username/Password boxes.
 * Set the background colour of the 'Log in' button
 * Set the background color of the Login Box.
* Set the color of the footer text.
* Set the colour of the text in the Login box.
* Set the colour of the 'Log in' text on the 'Log in' button 
* Set to have CSS rounded corners on your login box and the 'Log in' button
</code></pre>
Usually this require’s modification of CSS code to have the changes stick. This can lead to changes being overwritten on theme updates. This plugin is simple and allows you to easily change the options between your custom choices and the default ones that are set for your theme.

Style Admin

Want to style your Admin login pages for your clients in their corporate colors?  Sick of the default wordpress wp-admin login page?  Then this plugin …

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.

Style Admin vs Add Admin CSS