Free osCommerce 2.3.3 Admin Template Dark Red Style
Tested on Firefox and Chrome not tested on Opera and IE but I think it will work on both browsers.
How To Install?
First, Back up your store!
Second, rename configure.php in catalog > admin > includes in your new admin template.
Third, rename stylesheet.css in catalog > admin > includes in your admin store template.
Fourth, rename oscommerce.png in catalog > admin > images in your new admin template.
fifth, copy all admin files from your new admin template to your existing store.
Refresh your store then go to admin control panel.