Examine source code of Scratch Colors

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Scratch Colors",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(99, 184, 232)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(142, 179, 201)",
      "tab_background_text": "rgb(249, 230, 0)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(211, 196, 16)",
      "tab_line": "rgb(248, 242, 112)",
      "popup": "rgb(207, 205, 174)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(153, 42, 42)",
      "button_background_hover": "rgb(167, 183, 54)",
      "ntp_text": "rgb(255, 255, 255)",
      "tab_selected": "rgb(7, 176, 159)",
      "tab_text": "rgb(253, 253, 253)",
      "tab_loading": "rgb(248, 242, 112)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2bac97e8-a022-4e5c-a661-6d3af7e19435}"
    }
  }
}