I need help with css for and drupal?

[vistadude]

Ok I have a css code of a drupal theme, part of it I want to be transparent. So I did this:

}

#container .sidebar .block {
background-color: #000000; opacity: .0;
border: solid #000000 0px;
margin-top: 5px;
margin-bottom: 20px;
}

But the fact is it did not only make the background transparent for that block, but the text in it for some reason, and I did not put it on a setting to make that transparent. How do I make it so that only the background in transparent, and i need it to be 100% transparent.

the theme that I am modifying is brushed steel, here is the original css code for that section:

}

#container .sidebar .block {
background-color: #000000;
border: solid #000000 0px;
margin-top: 5px;
margin-bottom: 20px;
}