We don't currently offer complete white labeling.
However, for most organizations, this isn't an issue as:
You can change colors in the report
You can add an image to the front cover of the report (in addition to a logo)
You can remove our logo from reports
You can customize the content of emails
Emails sent from the site will appear to be sent from your email address.
It's not currently possible to:
Remove our logo from the questionnaire (it will appear in a thin blue bar at the top of the page)
Use a different web domain (e.g. 360feedback.yourcompany.com)
Style the questionnaire
Change the fonts used in the reports