Ok just change it to read
body
{
margin:0px;
padding:0px;
background-color:#ffffff;
font-family:Arial;
font-size:12px;
color:#000000;
}.
or if your going to use an image replace the background-color bit with
background:url('../images/xxxxx.jpg') center top no-repeat;
you can change the color to your preference...google css colors or goolge adobe colour wheel for some fun.
you can always change the permissions back to the original setting after you have finished your site.
Good tip though if your site is sitting live on a server viewable to the public, create a index.html file with an image saying that your site is coming soon, if some one comes accross your site thier browser will pick up the index.html first instead of the index.php.....when you finshed your site you can remove it to open it to the public.
Also i would recommend this mod for security http://www.expertzzz.com/Downloadz/view/406
