neilgee

This plugin adds support for placeholder text in browsers that don’t support this HTML5 feature including Internet Explorer 6.
The plugin just activates the placeholders.js script by James Allardice http://jamesallardice.github.io/Placeholders.js/
There is no further configuration required.
For HTML input elements use the placeholder attribute and add a value, this value is removed when a user inputs the field. http://coolestguidesontheplanet.com/add-a-label-into-a-text-input-field-in-a-html-form/#html5
The script is 4KB and is set to load in the footer and has no library dependencies.
<h3>Usage</h3>
Just activate the plugin which loads the script, their is no further configuration.

Placeholder Text

This plugin adds support for placeholder text in browsers that don't support this HTML5 feature.

Robert Chapin

Input fields on the WordPress admin screens have been nearly invisible since version 2.7. After a year of hacking CSS files to work around this problem, Matt suggested I make a plugin to override core CSS values. This plugin does just that.
Fix Admin Contrast now also corrects white point issues on iPad and similar displays. Without this plugin, the administrative table colors can look the same as the background color.
If you need even more contrast, consider my plugin called <a href="https://wordpress.org/plugins/high-contrast-admin/" rel="ugc">High Contrast Admin</a>

Fix Admin Contrast

Improves the visibility of administrative form fields and tables.

Placeholder Text vs Fix Admin Contrast