Examine source code of Proper Light White

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Proper Light White",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-012-1e971c5fbb8dec3acbd76dd6c6819de9.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(255, 255, 255)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(255, 255, 255)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(255, 255, 255)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "button_background_active": "rgb(217, 217, 217)",
      "button_background_hover": "rgb(233, 233, 233)",
      "icons": "rgb(0, 0, 0)",
      "ntp_background": "rgb(255, 255, 255)",
      "ntp_text": "rgb(0, 0, 0)",
      "popup_border": "rgb(255, 255, 255)",
      "popup_highlight_text": "rgb(0, 0, 0)",
      "popup_highlight": "rgb(233, 233, 233)",
      "sidebar_border": "rgb(255, 255, 255)",
      "sidebar_highlight_text": "rgb(0, 0, 0)",
      "sidebar_highlight": "rgb(173, 173, 173)",
      "sidebar_text": "rgb(67, 67, 67)",
      "sidebar": "rgb(255, 255, 255)",
      "tab_loading": "rgb(173, 173, 173)",
      "tab_text": "rgb(0, 0, 0)",
      "toolbar_bottom_separator": "rgb(255, 255, 255)",
      "toolbar_field_border": "rgb(255, 255, 255)",
      "toolbar_field_highlight_text": "rgb(34, 25, 77)",
      "toolbar_field_separator": "rgb(255, 255, 255)",
      "toolbar_top_separator": "rgb(255, 255, 255)",
      "toolbar_vertical_separator": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{70f41739-e9f1-4058-ad6a-9acba3ab87f8}"
    }
  }
}