Examine source code of synth grey calx

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "synth grey calx",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(57, 60, 60)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(0, 6, 10)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(3, 3, 3)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(0, 6, 10)",
      "popup": "rgb(69, 69, 70)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(0, 6, 10)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{612557f1-f3d4-4176-99c4-6c310f171ac1}"
    }
  }
}