Examine source code of Dark mode, Light yellow

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark mode, Light yellow",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-021-775b159da029a74f5c76e835cd65e9dc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(245, 255, 104)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(43, 43, 43)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(43, 43, 43)",
      "toolbar_field_text": "rgb(245, 255, 104)",
      "tab_line": "rgba(255, 255, 255, 0)",
      "popup": "rgb(245, 255, 104)",
      "popup_text": "rgb(0, 0, 0)",
      "button_background_active": "rgba(0, 0, 0, 0.19)",
      "button_background_hover": "rgba(0, 0, 0, 0.19)",
      "frame_inactive": "rgba(255, 255, 255, 0)",
      "icons_attention": "rgb(0, 0, 0)",
      "icons": "rgb(43, 43, 43)",
      "popup_border": "rgba(255, 255, 255, 0)",
      "tab_background_separator": "rgba(0, 0, 0, 0.37)",
      "tab_selected": "rgb(245, 255, 104)",
      "tab_text": "rgb(43, 43, 43)",
      "toolbar_bottom_separator": "rgba(255, 255, 255, 0)",
      "toolbar_field_border_focus": "rgba(255, 255, 255, 0)",
      "toolbar_field_border": "rgba(255, 255, 255, 0)",
      "toolbar_field_focus": "rgb(0, 0, 0)",
      "toolbar_field_highlight_text": "rgb(0, 0, 0)",
      "toolbar_field_highlight": "rgb(245, 255, 104)",
      "toolbar_field_text_focus": "rgb(245, 255, 104)",
      "toolbar_top_separator": "rgba(255, 255, 255, 0)",
      "tab_loading": "rgba(255, 255, 255, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fe4ef456-7697-42db-acc0-6de73ba44a3b}"
    }
  }
}