Examine source code of Colcha

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Colcha",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-011-d53e0d0d1538ed554a90e056a2f04eca.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(232, 232, 232)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(232, 232, 232)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(108, 171, 205)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(96, 125, 139)",
      "popup": "rgba(255, 255, 255, 0.93)",
      "popup_text": "rgb(0, 0, 0)",
      "button_background_active": "rgba(108, 171, 205, 0.57)",
      "button_background_hover": "rgba(108, 171, 205, 0.4)",
      "frame_inactive": "rgb(232, 232, 232)",
      "icons_attention": "rgb(255, 0, 21)",
      "icons": "rgb(0, 0, 0)",
      "ntp_background": "rgb(232, 232, 232)",
      "ntp_text": "rgb(0, 0, 0)",
      "popup_border": "rgba(255, 255, 255, 0.93)",
      "popup_highlight_text": "rgba(108, 171, 205, 0.57)",
      "popup_highlight": "rgb(108, 171, 205)",
      "sidebar_border": "rgba(57, 57, 57, 0.19)",
      "sidebar_highlight_text": "rgb(255, 255, 255)",
      "sidebar_highlight": "rgba(255, 0, 21, 0.32)",
      "sidebar_text": "rgb(57, 57, 57)",
      "sidebar": "rgb(232, 232, 232)",
      "tab_background_separator": "rgb(96, 125, 139)",
      "tab_loading": "rgb(0, 0, 0)",
      "tab_selected": "rgb(108, 171, 205)",
      "tab_text": "rgb(57, 57, 57)",
      "toolbar_bottom_separator": "rgba(57, 57, 57, 0.19)",
      "toolbar_field_border_focus": "rgb(96, 125, 139)",
      "toolbar_field_border": "rgb(96, 125, 139)",
      "toolbar_field_focus": "rgb(255, 255, 255)",
      "toolbar_field_highlight_text": "rgb(0, 0, 0)",
      "toolbar_field_highlight": "rgba(108, 171, 205, 0.67)",
      "toolbar_field_separator": "rgb(57, 57, 57)",
      "toolbar_field_text_focus": "rgb(0, 0, 0)",
      "toolbar_top_separator": "rgba(57, 57, 57, 0.19)",
      "toolbar_vertical_separator": "rgba(57, 57, 57, 0.19)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{be962fc4-4536-4266-9ccd-955f7a4031df}"
    }
  }
}