Which version are you using ? If You have the opportunity, please provide access to the HP forum, we will try to help You
To change the background of all titles search the veilon.css this code
.ipsType_sectionTitle {
font-size: 20px;
color: #b7bacd !important;
padding: 17px 50px;
background-color: #313448;
}
and replace
background-color: yourhtmlcolor;
To change background on a specific title or add a custom veilon.css
li[data-categoryid="yourcategoryid"] .ipsType_sectionTitle { background: yourcode; }
ID category, and you can learn from it links, for example
/forum/42-community-led-resources-to-view/
The category ID is 42