Joe Dolson

Adds a custom field to your post editing screens to add custom styles applied only on that page or post.
Attach custom styles to any page, post, or custom post type. Separate styles can be attached for print, screen, or mobile. You can also store your own library of frequently-used styles.
How to use the style library:
<ol>
<li>Add the styles you want on your settings page.</li>
<li>Navigate to an article which requires specific styles.</li>
<li>Select the library style from the drop down, leaving the style textarea blank.</li>
<li>Update or post the new document.</li>
</ol>
A newly-selected style from the style library will always overwrite any previous hand-written styles. If you wish to alter the library styles for a specific page, you can do this in the textarea after you’ve saved the page with the style library template.
By default, editing your saved stylesheets will have no impact on previously saved post-specific styles; set the option to pull styles from the library to change this.
Note: custom styles will not be included on archive pages; only on single post/Page views.
The use you’ll get out of this plugin depends on the flexibility of the theme you’re using and your own knowledge of CSS (Cascading Style Sheets).

WP Post Styling

Define custom styles for any post, page, or custom post type. Example: journal-style publications which want to create a unique design for articles.

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 …

WP Post Styling vs Style Admin