Metric count on multiple indices

Hi All,
I'm using ES and Kibana on my thesis work and I faced up to the count metric
the question is, is there a way to count grouping by index ?
I mean, I would like to get 1 point even if the searched term (e.g color:red) is present more than once into the index; of course if the term is present in other index too I would get the count of index where term is present.

thanks in advance

Would using the "Unique Count" aggregation on an index pattern that points to these multiple indices address your use case?

You can group and count by index but I don't know of a way to do a unique count. What's called "Unique Count" in Kibana that @tbragin has mentioned is using the Cardinality Aggregation which is fast but not accurate - You can improve accuracy but I am not sure you can ever be sure the data is 100% accurate.

-- Asaf.