vxlan host-reachability-protocol evpn-bgp vrfblue is not successful

Make sure that the vrf which you are trying to map is configured.

Can we have vtep-ip-global as loopback ip

Yes.This ip is the source ip of the tunnel.

sh bgp l2vpn evpn does not show the multicast entries

Make sure that your route is reachable using any static/dynamic (isis/ospf...) protocol.

Also make sure that bgp neighborship is established.

Ping is not working for a particular vnid

Ensure that all the interfaces are up and running

Ensure that source mac address is learnt on source VTEP on each VTEP using show bridge.

Ensure that you can ping tunnel destination IP, ie. you have a route to reach the destination VTEP.

Ensure that bgp neighborship is established, have proper router-id's configured

Ensure that you have imported/exported the route correctly using route-target.Ensure unique RD in all VRFs

Also ensure that on all the VTEPs, access port is mapped to respective/relevant VNID