[TYPO3-templavoila] change class or background

[Styrmir Magnússon]

Hello

Can I use templaVoila to change background color of a <div> tag

My template is like this

<div class="group">
<div class="middle-left">
<div class="name">1st. group</div>
<div class="date">23. - 29. july</div>
<div class="age">12 - 15 years</div>
</div>

css file is like this

.group {
background-color:#ffcc00;
}

I want to have a drop down box in the FCE that I can use to change the 
background color of the div tag

can I either change the first class to something else like say group1, 
group2, group3,...
or
change the background-color of the css either by using constants or 
affecting the css file

I have read the Document for futuristic template building, chapter 1.5. 
Miscellaneous but I don't understand how it works.

Regards
Styrmir