Examine source code of Focus Gradient

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "Focus Gradient",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(235, 176, 176, 0)",
      "toolbar_field": "rgba(235, 176, 176, 0)",
      "toolbar_field_text": "rgb(235, 176, 176)",
      "tab_line": "rgb(0, 255, 200)",
      "popup": "rgb(134, 58, 70)",
      "popup_text": "rgb(187, 188, 221)",
      "tab_loading": "rgb(0, 255, 200)",
      "bookmark_text": "rgb(187, 188, 221)",
      "frame": "rgb(215, 234, 234)",
      "tab_background_text": "rgb(0, 0, 0)"
    }
  }
}