This is a solution I found at https://devanswers.co/how-to-fix-authentication-is-required-to-create-a-color-profile-managed-device-on-ubuntu-20-04-20-10/ while trying to solve this annoying problem.
vi /etc/polkit-1/localauthority.conf.d/02-allow-colord.conf
add:
polkit.addRule(function(action, subject) {
if ((action.id == "org.freedesktop.color-manager.create-device" ||
action.id == "org.freedesktop.color-manager.create-profile" ||
action.id == "org.freedesktop.color-manager.delete-device" ||
action.id == "org.freedesktop.color-manager.delete-profile" ||
action.id == "org.freedesktop.color-manager.modify-device" ||
action.id == "org.freedesktop.color-manager.modify-profile") &&
subject.isInGroup("{users}")) {
return polkit.Result.YES;
}
});
Save it! “... Now reboot Ubuntu and try logging in again over RDP / Windows Remote Desktop and the popups should be gone ….“