The addition of profile customization did some strange things to the stylevars. The sidebar links there are defined in "#sidebar_container a" which is defined by a variable called "moduleinactive_link_color" which is actually defined by the color set in stylevar "header_background" If you aren't using custom profilization, I would just define it in additional.css as:
HTML Code:
#member_content #sidebar_container a { color: green;}