Examine source code of Gray,colored theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Gray,colored theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-023-f741aad3989b46322a7840a425068429.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(83, 82, 82, 0.03)",
      "toolbar_text": "rgb(255, 242, 242)",
      "frame": "rgb(71, 70, 70)",
      "tab_background_text": "rgb(251, 153, 112)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(253, 253, 253)",
      "tab_line": "rgba(174, 6, 245, 0.9)",
      "popup": "rgb(71, 70, 70)",
      "popup_text": "rgb(253, 248, 248)",
      "button_background_active": "rgba(3, 251, 3, 0.65)",
      "button_background_hover": "rgb(113, 112, 112)",
      "frame_inactive": "rgb(71, 70, 70)",
      "icons_attention": "rgb(15, 255, 1)",
      "icons": "rgb(1, 125, 255)",
      "popup_border": "rgb(15, 255, 1)",
      "sidebar": "rgb(249, 243, 241)",
      "tab_selected": "rgb(249, 176, 5)",
      "tab_text": "rgb(0, 0, 0)",
      "toolbar_field_border": "rgba(174, 6, 245, 0.9)",
      "toolbar_field_focus": "rgb(50, 6, 154)",
      "toolbar_top_separator": "rgb(1, 125, 255)",
      "toolbar_vertical_separator": "rgb(1, 125, 255)",
      "tab_loading": "rgba(174, 6, 245, 0.9)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{445da63a-8501-4d83-af53-cc2a76f9b9d3}"
    }
  }
}