You should only need to make the update in the places that I have specified:
spry_custom.css
.AccordionPanelTab {
background-color: #eeeeee;
border: 0;
border-top: solid 1px white;
padding:10px;
}
Main.dwt.php template near line 165, here is the exact line of code:
div.setAttribute('style',"background-color:#3375A2; color: white; border-top:0px;");
The color of the text is inherited from the body, if you would like to explicitly define the color yourself you can do so in the .AccordionPanelTab css mentioned above like this:
spry_custom.css
.AccordionPanelTab {
background-color: #eeeeee;
border: 0;
border-top: solid 1px white;
padding:10px;
color: #555555;
}