Hi @Dhanushka.Samarakoon, Welcome to the community and for making your first post. I found this AppD Docs page that shares some insights into what those colors mean. I recommend you review this documentation and any other relevant to help you understand more about Health Rules.  https://docs.appdynamics.com/display/PRO45/Health+Rule+Management Here is a quick snapshot of the info you asked for: Green is healthy Yellow/orange is a warning condition  Red is a critical condition Grey indicates that the status of the health rule is unknown (for example, if the Controller cannot gather the data necessary to evaluate the rule)  ... View more