Forum Small bit of style variable help needed

[محروم.كوم]

www.hmandsforums.oliwy.net/forums is the link to my board. In google chrome, you'll notice there's a grey/white line going down the length of my sidebar on the left side of it. I have searched the sidebar style variables and have come up empty. So what style variable would I have to edit, for me to reshade this line from its default color to a black hex code like #000000 #161616 or #141414? __DEFINE_LIKE_SHARE__