Examine source code of Dark Minimal FF

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "darkminimalff@eastmarch.github.com",
      "strict_min_version": "67.0"
    }
  },
  "name": "Dark Minimal FF",
  "version": "1.1",
  "description": "Minimalistic dark theme for Firefox. Very low contrast.",
  "theme": {
    "colors": {
      "tab_line": "#5F4F80",
      "tab_background_text": "#707070",
      "frame": "#333333",
      "frame_inactive": "#3A3A3A",
      "tab_loading": "#5F4F80",
      "icons_attention": "#5F4F80",
      "icons": "#828282",
      "toolbar": "#3A3A3A",
      "bookmark_text": "#999999",
      "toolbar_top_separator": "#404040",
      "toolbar_bottom_separator": "#404040",
      "toolbar_vertical_separator": "#616161",
      "toolbar_field": "#3A3A3A",
      "toolbar_field_text": "#B3B3B3",
      "toolbar_field_focus": "#3A3A3A",
      "toolbar_field_border": "#3A3A3A",
      "toolbar_field_separator": "#616161",
      "toolbar_field_border_focus": "#3A3A3A",
      "toolbar_field_highlight": "#5F4F80",
      "toolbar_field_highlight_text": "#DBE4F0",
      "button_background_hover": "#525252",
      "button_background_active": "#5F5F5F",
      "popup": "#3A3A3A",
      "popup_text": "#999999",
      "popup_border": "#404040",
      "popup_highlight": "#5F4F80",
      "popup_highlight_text": "#DBE4F0",
      "ntp_text": "#6F6F6F",
      "ntp_background": "#333333",
      "sidebar": "#3A3A3A",
      "sidebar_text": "#999999",
      "sidebar_border": "#404040",
      "sidebar_highlight": "#5F4F80",
      "sidebar_highlight_text": "#DBE4F0"
    }
  }
}