Custom Histogram Legend

Hello,

I’m using a postgresql database. I have 8 queries and I want each query to appear as a different colour in a histogram. I also want the legend of the histogram to display a certain string for each query. Right now, everything appears as “count” in the legend. A sample query is below.

SELECT
  now() as time, 'string' AS metric, value_column as value
FROM
  table
WHERE
  id = '$LogIdentifier' and timestamp >= $__timeFrom() and timestamp <= $__timeTo()