Examine source code of Simple Colors: Red

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple Colors: Red",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-019-7ce748211c61f9059493d4c4378e8a74.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(20, 0, 0, 0.4)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(120, 0, 0)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(50, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgba(255, 0, 0, 0.5)",
      "popup": "rgb(50, 0, 0)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgba(255, 190, 190, 0.2)",
      "button_background_hover": "rgba(255, 190, 190, 0.2)",
      "frame_inactive": "rgba(120, 100, 100, 0.2)",
      "icons_attention": "rgba(250, 230, 50, 0.8)",
      "ntp_background": "rgb(40, 0, 0)",
      "ntp_text": "rgb(255, 255, 255)",
      "popup_border": "rgba(255, 0, 0, 0.5)",
      "popup_highlight": "rgba(255, 190, 190, 0.2)",
      "sidebar_border": "rgb(110, 0, 0)",
      "sidebar": "rgb(80, 0, 0)",
      "toolbar_bottom_separator": "rgb(110, 0, 0)",
      "toolbar_field_border": "rgba(255, 0, 0, 0.5)",
      "toolbar_field_highlight": "rgba(255, 190, 190, 0.2)",
      "toolbar_top_separator": "rgb(110, 0, 0)",
      "toolbar_vertical_separator": "rgba(255, 0, 0, 0.5)",
      "tab_loading": "rgba(255, 0, 0, 0.5)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ed16b902-150f-4d72-8188-2bae7be6f9c5}"
    }
  }
}