Domain Groups for WHMCS will help you to get organized your domains, create as much as you want groups and add a color to each of them
Supports WHMCS Blend and V4 Template
Assign a domain to a group
Show this group data on invoices
If the domain group does not assign then show “ungrouped”
Group domains of clients but also add what kind of hosting package he/she offers to his/her clients. Its not connected to hosting packages within WHMCS though.