elasticsearch calculate average of unique values
<p>How can I dynamically calculate the average of unique values in elasticsearch?</p>

<pre><code>{ "price" : 10000, "color" : "red" }
{ "price" : 20000, "color" : "red" }
{ "price" : 30000, "color" : "green" }
{ "price" : 15000, "color" : "blue" }
{ "price" : 12000, "color" : "green" }
{ "price" : 20000, "color" : "red" }
{ "price" : 80000, "color" : "red" }
{ "price" : 25000, "color" : "blue" }
</code></pre>

<p>In the above data, how can I get the unique values of the "color" field and then the averages for each of the unique "color" fields?</p>