C# Linq - Given two lists, how do I tell if either of them are contained in each other -

I have two lists:

  list: "brown" "green" "yellow "Orange" List B: "Yellow" "Orange"   
 If the true list or list is contained in each other then I want to return the truth. In this case ListB is a part of ListA, it is not necessary that List B will be small.  
 The only solution I can think is that the name of the union on both sides, i.e. ListB with ListB, ListB with ListA, and if true then only if both  < P> Is this the best way, any other way?  
 I'm hoping for a Linq solution   
 
 
 you can try :  
  int count = ListA. Insight (List B). Content ();