Examine source code of THFv8

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "THFv8v2",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(68, 71, 73)",
      "toolbar_text": "rgb(252, 179, 0)",
      "frame": "rgb(68, 71, 73)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(68, 71, 73)",
      "tab_line": "rgb(252, 179, 0)",
      "popup": "rgb(68, 71, 73)",
      "popup_text": "rgb(252, 179, 0)",
      "button_background_active": "rgb(252, 179, 0)",
      "button_background_hover": "rgb(0, 114, 206)",
      "icons_attention": "rgb(252, 179, 0)",
      "icons": "rgb(252, 179, 0)",
      "ntp_background": "rgb(68, 71, 73)",
      "ntp_text": "rgb(252, 179, 0)",
      "popup_border": "rgb(252, 179, 0)",
      "popup_highlight": "rgb(252, 179, 0)",
      "sidebar_highlight_text": "rgb(252, 179, 0)",
      "sidebar_text": "rgb(252, 179, 0)",
      "tab_background_separator": "rgb(252, 179, 0)",
      "tab_loading": "rgb(252, 179, 0)",
      "tab_selected": "rgb(68, 71, 73)",
      "tab_text": "rgb(252, 179, 0)",
      "toolbar_bottom_separator": "rgb(252, 179, 0)",
      "toolbar_field_border_focus": "rgb(252, 179, 0)",
      "toolbar_field_border": "rgb(252, 179, 0)",
      "toolbar_field_highlight_text": "rgb(252, 179, 0)",
      "toolbar_field_separator": "rgb(252, 179, 0)",
      "toolbar_field_text_focus": "rgb(68, 71, 73)",
      "toolbar_top_separator": "rgb(252, 179, 0)",
      "toolbar_vertical_separator": "rgb(252, 179, 0)"
    },
    "body": {
      "background": [
        "url(https://intranet/BG%20(2).jpg) !important"
      ],
      "background-size": [
        "cover !important"
      ]
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dccff27d-1080-4166-a72e-f6fee043d7bc}"
    }
  }
}