CampusGroups allows you to either a) create a custom template with your group logo, colors, etc. that you can use and re-use when creating newsletters or b) to select a default template while composing an email.
Manage your group
Click on Emails
Click Compose Email
Select the members to whom you want to send an email, and select Compose email for selected groups
When on the Template tab, select any of the available templates
Please contact firstname.lastname@example.org with any questions.