Nazmur Rahman

Text Selection Color plugin helps to change the color of the selected text in the website easily.
Features:
<ul>
<li>User can change text color and text background color from plugin settings page with color picker.</li>
<li>Changes can be seen as preview in the plugin settings page.</li>
</ul>
<h4>Translators</h4>
<ul>
<li>Bengali (bn) – <a href="http://nazmurrahman.com/" rel="nofollow ugc">Nazmur Rahman</a></li>
<li>Spanish (es) – <a href="http://firstsiteguide.com/" rel="nofollow ugc">Ognjen Djuraskovic</a></li>
<li>Serbian (sr) – <a href="http://firstsiteguide.com/" rel="nofollow ugc">Ognjen Djuraskovic</a></li>
</ul>

Text Selection Color

Text Selection Color plugin helps to change the color of the selected text in the website easily.

nektobit

A lightweight (8Kb minified, 2.9Kb gzipped) script to let users share their text selections to social networks, in desktop browsers. (Yes, like Medium). 
Based on Sharect.js
<ul>
<li>Supports adding custom icons (for now using php snippet)</li>
<li>You can also control the color of the tooltip widget (also using php code)</li>
</ul>
<a href="https://nektobit.github.io/WP-Sharect/#documentation" rel="nofollow ugc">Documentation</a>
Millstones
The plugin is under active development, I welcome any feedback.
<ul>
<li>Add widget color picker</li>
<li>Adding social media icons from the admin interface</li>
<li>Optional meta tags</li>
</ul>

Sharect WP

The plugin allows you to highlight text on your website and share it on social networks

Text Selection Color vs Sharect WP