Change background color of individual widgets

First of all - thanks for this fabulous theme. I have looked at many different ones, nothing comes close. Donation made....

I am looking for a way to change background colors on individual widgets (category, pages, different text blocks) in order to put a little life into the sidebars. I know I can change the general sidebar color and the general widget color, but how about a different color for each widget? Can that be done?

Thanks.