Unclear how to select nodes with colons

[boxabirds]

JSON keys in maps can be any value, yet it seems that this proprietary method of JSON selector seem to only support a subset of tags. For instance, in HTML, there are numerous open data keys that include colons. How do I write a selector using your method for this data source below?

{
  "users": [
    {
      "name": "John",
      "og:friends": [
        {
          "name": "F1"
        }
      ]
    },
    {
      "name": "Joe",
      "og:friends": [
        {
          "name": "F2"
        }
      ]
    },
    {
      "name": "Jane",
      "og:friends": [
        {
          "name": "F3"
        }
      ]
    }
  ]
}

(an aside: I have been expecting any JSON selector parser to be able to handle natively the selectors generated by jsonselector.com as test cases.)