You should issue the ip route vrf ce1 0.0.0.0 0.0.0.0 172.16.0.1 global command to ensure that the route in a VPN routing and forwarding (VRF) named ce1 uses the default gateway address of 172.16.0.1, which is commonly accessible from all other addresses on the router but does not exist in the ce1 table. The global keyword configures VRF ce1 to use the 172.16.0.1 gateway that is present in the global routing table instead of attempting to look it up in the VRF ce1 routing table.

The global routing table stores paths that can be accessed by using any of the addresses on the router, not just the addresses associated with a given VRF. However, the global keyword applies only to the gateway address in the command, not to the entire static route. To configure a static route to apply to a given VRF, you should issue the vrf keyword along with the name of the VRF to which you want the route to apply. In this scenario, the ip route vrf ce1 0.0.0.0 0.0.0.0 172.16.0.1 global command configures a default route for the VRF named ce1.
You should not issue the ip route vrf ce1 0.0.0.0 0.0.0.0 172.16.0.1 permanent command in this scenario. The permanent keyword ensures that a route will not be removed from the associated VRF table even if the interface associated with the route is shut down. There are no conditions in this scenario that require you to issue the command with the permanent keyword.
You should not issue either the ip route vrf 0.0.0.0 0.0.0.0 172.16.0.1 global command or the ip route vrf 0.0.0.0 0.0.0.0 172.16.0.1 permanent command in this scenario. Neither of those commands contain valid syntax.