Forum diiferent colors for each category head on forumhome
 

hi, want to make a separate colors for each category head, as i can change the colors of all categories head by using css,
.forumhead{
background:#ff0000;
}

but how to set different colors for every category head?
i am looking for something like this
https://www.vbulletin.com/forum/show...-in-forum-home

but i need it for vbulletin 4 forum head.