There should be an option for your Theme’s Settings, it’s probably called Simplicity. The first tab there is called Theme Options. At the very bottom of the page is a box for Custom CSS like this:
Add the following code in the box to change the footer to white:
#footer-widgets-container {background: #fff}
#footer-container {background: #fff}
Then save your changes and have a look. Usually I test these things out on my site before I give advice such things but in this case I haven’t got the core files to make sure it works.
Try adding this to the Custom CSS box underneath the code from before:
#footer-widgets-container p {color: #000}
#footer-widgets-container li {color: #000}
#footer-container p {color: #000}
#footer-container li {color: #000}
This *should* target text properties inside both footer areas.
You can always ask one of the guys over at the Woo Themes Forum – they’ll help you out on Woo Themes related tweaks and issues: http://www.woothemes.com/support-forum/