A customer recently asked me how to create a view (or list) of offline servers. Initially this seemed a bit tricky because offline servers are gray, but this isn't actually a state. It turns out the key is to look at the Health Watcher as this is what runs on the MS and turns a server "gray."
Server Down View
*excludes SCOM infra servers
Create a State Widget
Scope - Microsoft.SystemCenter.AgentWatchersGroup
Criteria - Display only Critical