Examine source code of BasicGray1w2

{
  "theme": {
    "images": {
      "theme_frame": "BasicGray1w2Header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#000"
    }
  },
  "version": "2.0",
  "name": "BasicGray1w2",
  "manifest_version": 2,
  "description": "My first Firefox persona.\nGray Gradient with colored in Firefox logo.\n\nJust tried a basic gray gradient and made an emboss etch using the Firefox logo as a guide.\nColored it in with some basic strokes and blended it in.\nKinda looks like it was colored with markers a bit I think.\nI wonder if I shoulda added a black nose... hmm.\n\nSimple and easy to the eyes was the overall idea.\n\nEnjoy."
}