You're using the default behavior of initials based canvas and avatar. You can't change those colors directly from parameters as they're based off their initials. Edit your canvas and avatar fields within CB > Field Management and you can adjust both to static images which you can supply custom images for. New images can be uploaded to the below locations.
Avatar
/components/com_comprofiler/plugin/templates/default/images/avatar
Canvas
/components/com_comprofiler/plugin/templates/default/images/canvas