The breadcrumb skin object uses the "skinobject" class by default.  I suggest you set your breadcrumb to a new class name and style it from there:

In the css file:

.crumbs, .crumbs a{
font: 12px "Times New Roman", Times, serif;
color: white;
text-decoration: none;
}

If you are using the HTML/XML skinning method, do this in the xml file:

<Object>
<Token>[BREADCRUMB]</Token>
 <Settings>
  <Setting>
  <Name>RootLevel</Name>
  <Value>0</Value>
  </Setting>
  <Setting>
  <Name>Separator</Name>
  <Value><![CDATA[&nbsp;&raquo;&nbsp;]]></Value>
  </Setting>
  <Setting>
  <Name>CssClass</Name>
  <Value>crumbs</Value>
  </Setting>
 </Settings>
</Object>

If using the ASCX skinning method, do it like this in the ascx file:

<dnn:BREADCRUMB runat="server" id="dnnBREADCRUMB" CssClass="crumbs" RootLevel="0" Separator="&nbsp;&raquo;&nbsp;" />

Hope this gets you on the right track...

I just made up a class name, and happened to call it "crumbs". It can be any name you like, as long as it isn't used elsewhere and it doesn't start with a numeric...

The "a" denotes a link - the breadcrumb skin object is displayed as links.  I used text-decoration: none in order to keep it from being underlined.

This was just a simplified example... in practice I would control the style more like this:

.crumbs{
font: 12px "Times New Roman", Times, serif;
font-weight: bold;
color: white;
}
a.crumbs:link, a.crumbs:visited{
text-decoration: none;
color: white;
}
a.crumbs:hover{
text-decoration: underline;
color: red;
}
a.crumbs:active{
text-decoration: underline;
color: white;
}

This should give breadcrumb links (and any already visited) in bold white text that turns red and underlined on mouse-over, turning back to white but staying underlined on the currently active item.

Then I'd put it on the page like this (I skin using the ASCX method):

<span class="crumbs">You are here:&nbsp;&nbsp;</span><dnn:BREADCRUMB runat="server" id="dnnBREADCRUMB" CssClass="crumbs" RootLevel="0" Separator="&nbsp;&raquo;&nbsp;" />