Examine source code of Eyestrain

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Eyestrain",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(131, 0, 255)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(242, 254, 255)",
      "toolbar_field_text": "rgb(0, 7, 255)",
      "tab_line": "rgb(0, 0, 0)",
      "popup": "rgb(241, 245, 245)",
      "popup_text": "rgb(0, 7, 255)",
      "tab_loading": "rgb(0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5354893e-d1fa-46f9-970a-130741db628e}"
    }
  }
}