twenty ten how to change tab colors and highlight tab for selected page

My name is Brian. I work in health care, and I know nothing about blogs or CSS. I created a .com WordPress blog last weekend here: http://briandailyabroad.wordpress.com/

I’m not sure which version of WordPress I’m using, and I don’t see the version indicated anywhere in my Dashboard. My theme is twenty ten. I paid $30 for a WordPress upgrade to be able to make changes to the CSS code. In the menu, I would like to make all the tabs white with black text. And I would like the tab for the selected page to be black with white text, so the viewer can tell which tab is selected. I have looked at two related threads in this forum:
1) http://en.forums.wordpress.com/topic/custom-menu-tab-colors-in-twenty-ten?replies=15
2) http://wordpress.org/support/topic/twenty-ten-colour-tabs?replies=6

However, after 3 hours of trial and error, I can’t figure out how to type the CSS code to make it work for me. Which doesn’t surprise me, because I don’t know anything about blogs or CSS code. Please type out exactly what the code should look like, because I plan on copying and pasting your code into my dashboard, then clicking preview, then keeping it if it works.

If I’m asking something that can’t be done, please let me know and I will ask WordPress for a $30 refund and settle for what I have now.

Thank you for your help and for your patience.
Brian

My code: `#access ul li.current_page_item > a,
#access ul li.current_page_parent > a,
#access ul li.current-menu-ancestor > a,
#access ul li.current-menu-item > a,
#access ul li.current-menu-parent > a {
color: #fff;
}
* html #access ul li.current_page_item a,
* html #access ul li.current_page_parent a,
* html #access ul li.current-menu-ancestor a,
* html #access ul li.current-menu-item a,
* html #access ul li.current-menu-parent a,
* html #access ul li a:hover {
color: #fff;
}`