@rapid3dme

add this example to the custom css

#wpforo #wpforo-wrap .wpfl-1:nth-of-type(1) .wpforo-category {
background-color: #ff9900 !important;
}
#wpforo #wpforo-wrap .wpfl-4:nth-of-type(2) .wpforo-category {
background-color: #ff4488 !important;
}
#wpforo #wpforo-wrap .wpfl-1:nth-of-type(3) .wpforo-category {
background-color: #009900 !important;
}
#wpforo #wpforo-wrap .wpfl-1:nth-of-type(4) .wpforo-category {
background-color: #ff1100 !important;
}
#wpforo #wpforo-wrap .wpfl-1:nth-of-type(5) .wpforo-category {
background-color: #331100 !important;
}
#wpforo #wpforo-wrap .wpfl-1:nth-of-type(6) .wpforo-category {
background-color: #886688 !important;
}
#wpforo #wpforo-wrap .wpfl-1:nth-of-type(7) .wpforo-category {
background-color: #bb1100 !important;
}

and replace the color codes according to your wishes

@rapid3dme

I see you're trying, but you changed the layout class to layout 2 (wpfl-2), but you're not using layout 2, just 1 and 4
use the code above and it will work

#wpforo #wpforo-wrap .wpfl-2:nth-of-type(1) .wpforo-category {
background-color: #2d4159 !important;
}

#wpforo #wpforo-wrap .wpfl-2:nth-of-type(2) .wpforo-category {
background-color: #0677A1 !important;
}

#wpforo #wpforo-wrap .wpfl-2:nth-of-type(5) .wpforo-category {
background-color: #0677A1 !important;
}