How to deduplicate elements using jq

Input file

some:
  awesome:
    members:
      - green
      - yellow
      - blue
      - red
      - green

Deduplication

[arch:devopsinuse main()] yq -o=json eval  /tmp/deduplicate.yaml | jq '.some.awesome.members  | group_by(.) | map(select(length>1) | .[0])'

[
  "green"
]