Examine source code of Dark glow

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "Dark glow",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat-x"
      ]
    },
    "colors": {
      "toolbar": "rgb(25, 25, 25)",
      "toolbar_field": "rgb(60, 60, 60)",
      "toolbar_field_text": "rgb(230, 230, 230)",
      "tab_line": "rgb(230, 240, 230)",
      "popup": "rgb(40, 40, 40)",
      "popup_text": "rgb(230, 230, 230)",
      "tab_loading": "rgb(230, 240, 230)",
      "bookmark_text": "rgb(230, 230, 230)",
      "frame": "rgb(30, 30, 30)",
      "tab_background_text": "rgb(200, 200, 200)"
    }
  }
}