curl --request POST \
  --url https://api.dirtroad.dev/tools/color-converter/rgb-to-hsl \
  --header 'Content-Type: application/json' \
  --header 'X-Payment: <api-key>' \
  --data '
{
  "r": 255,
  "g": 0,
  "b": 0
}
'

{
  "original": {
    "r": 123,
    "g": 123,
    "b": 123
  },
  "result": {
    "h": 180,
    "s": 50,
    "l": 50
  }
}