Examine source code of MarianaSL

{
  "description": "Plain dark bluish background, with whitish foreground.",
  "manifest_version": 2,
  "name": "MarianaSL",
  "theme": {
    "colors": {
      "bookmark_text": "#d8dce0",
      "button_background_active": "#424957",
      "button_background_hover": "#424957",
      "frame": "#20242a",
      "icons": "#d8dce0",
      "icons_attention": "#20242a",
      "ntp_background": "#20242a",
      "ntp_text": "#d8dce0",
      "popup": "#20242a",
      "popup_border": "#20242a",
      "popup_highlight": "#2D333D",
      "popup_highlight_text": "#d8dce0",
      "popup_text": "#d8dce0",
      "sidebar": "#20242a",
      "sidebar_border": "#20242a",
      "sidebar_highlight": "#20242a",
      "sidebar_highlight_text": "#d8dce0",
      "sidebar_text": "#d8dce0",
      "tab_background_separator": "#20242a",
      "tab_background_text": "#d8dce0",
      "tab_line": "#20242a",
      "tab_loading": "#d8dce0",
      "tab_selected": "#2D333D",
      "toolbar": "#20242a",
      "toolbar_bottom_separator": "#2f353e",
      "toolbar_field": "#2f353e",
      "toolbar_field_border": "#20242a",
      "toolbar_field_border_focus": "#20242a",
      "toolbar_field_focus": "#2f353e",
      "toolbar_field_separator": "#20242a",
      "toolbar_field_highlight": "#4C586C",
      "toolbar_field_text": "#d8dce0",
      "toolbar_field_text_focus": "#d8dce0",
      "toolbar_top_separator": "#20242a",
      "toolbar_vertical_separator": "#20242a"
    }
  },
  "version": "2.0"
}