Hi Preston,
You are looking to edit the template, /skin1/customer/main/welcome.tpl
You'll see this code:
Code:
{if ($active_modules.Greet_Visitor ne "") and ($smarty.cookies.GreetingCookie ne "") and $logout_user eq ''}
{assign var="_name" value=$smarty.cookies.GreetingCookie|replace:"\'":"'"}
<h3>{$lng.lbl_welcome_back|substitute:"name":$_name} </h3>
{elseif $lng.lbl_site_title}
<h3>{$lng.lbl_welcome_to|substitute:"company":$lng.lbl_site_title}</h3>
{else}
<h3>{$lng.lbl_welcome_to|substitute:"company":$config.Company.company_name}</h3>
{/if}
{$lng.txt_welcome}
You may want to assign a new class (I would use a div) - or use the h3 tag... and edit the h3 tag in your CSS (or make a new class and call it from a div.
Clear? if you know html, this will be easy. Let us know if you need help.