By default the background of WebHub's article edit window is set to white. To change the default background color of the Article Edit window, the fck_editor.css file has to be changed in QPS Server: This file can be found at the following location:

QPSServer Installation Directory\webapps\WebHub\thirdParty\FCKeditor2.5\editor\skins\default

Look for the following string and change the background color line to a web color of your choice using the same syntax as is used for the white background definition.

padding: 1px;
margin: 0;
background-color: #ffffff;