Short answer
HubSpot's KB: users with a Core seat and free tools users can create one One-on-One page with default HubSpot branding. With a Sales or Service seat, customize the logo, company info and colors in account settings, which also apply to documents and quotes. With the Brands add-on, the selected brand sets the logo.
1. Meetings tool
The meetings intro in my demo portal.

2. Brand kit
See brand kit setup.