grigori991

Plugin registeres simple widget within wordpress blog, that allows any visitor to change background 
color of theme. Actually it doesn’t change theme’s css file, but renders some style tag to user 
browser, that change the color locally. 
New background color associates only with user, that setted the color, and it tracks from cookie. 
So, if first visitor sets background color to ‘Rose’, second visitor can choose ‘Lime’ and third can 
leave that attribute to default and everyone get what they want at same time. 
If blog visitor sets background color to ‘Default’, browser explicitly deletes the cookie. Otherwise, 
cookie deletes itself after 30 days. 
Widget uses 4 ‘web-safe’ colors – #00FF00 (lime), #00FFFF (bluegreen), #9933FF (violet) and
FF0033(rose).

BGColor Setter

BGColor Setter plugin sets up the widget, that allows any visitor of blog to dynamically and graphically change the background color.

Robert Chapin

Input fields on the WordPress admin screens have been nearly invisible since version 2.7. The problem was so severe that Matt suggested I make a plugin to override core CSS values for anyone who wanted more contrast. Following community feedback, I created this extra plugin specifically for high contrast.
This plugin adds Admin Color Scheme options that dramatically change the appearance of form fields, table rows, and background colors in the admin pages. It is not intended to follow the design principles of the built-in style sheets. If this is too much for your needs, then also consider my plugin with more subtle effects called <a href="https://wordpress.org/plugins/fix-admin-contrast/" rel="ugc">Fix Admin Contrast</a>

High Contrast Admin

Adds admin color schemes for the visually impaired.

BGColor Setter vs High Contrast Admin