Magento – Change the text color of system emails

NOTE: In my answer I will describe how to do this for Magento's default package and theme. This should work in the same way for the RWD package and <SCSS> files. The important part is step 2 and to notice that there are multiple selectors in which the background color is defined.

To change the background color of Magento e-mail templates in Magento CE 1.9.1.0 do the following.

1. Copy the <CSS> file

   skin/frontend/base/default/css/email-inline.css

   to

   skin/frontend/YOURPACKAGE/YOURTHEME/css/email-inline.css

2. Open this file. The default background color for emails used by Magento is #ebebeb. This color is defined in several places. You need to find the following selectors

   body {
       margin: 0;
       padding: 0;
       text-align: left;
       color: #333333;
       background-color: #ebebeb;
   }
   

   which is around line 33, and

   body {
       background: #ebebeb;
       font-size: 12px;
       margin: 0;
       padding: 0;
   }
   

   which is around line 55, and

   html, 
   #background-table {
       background-color: #ebebeb;
   }
   

   which is around line 83

3. change the value of the background and background-color properties to (e.g.) #fff.

4. Make sure to flush all cache (just in case...)

This should give you a white background for all Magento email templates.

don't need to install extension and make load on site. go to
\app\locale\en_US\template\email\newsletter_subscr_success.html
delete full page content . and from now you don't get any mail on news later subscription.