Hi David,
Create 2 variables
Min_Criteria=Min([Minmaxalert].[Value]) In([Criteria])
Max_Criteria=Max([Minmaxalert].[Value]) In([Criteria])
Create Conditional Formatting Rule (Alert) ,
Value=Min_Criteria , then background "Red color"
Add subalert
Value=Max_Criteria , then background "Green color"
Result:
