Examine source code of Dusk

{
  "manifest_version": 3,
  "name": "Dusk",
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "nova-dusk@mozilla.org",
      "strict_min_version": "153.0"
    }
  },
  "theme": {
    "colors": {
      "frame": [
        245,
        236,
        255
      ],
      "frame_inactive": [
        225,
        216,
        235
      ],
      "toolbar": [
        255,
        255,
        255
      ],
      "toolbar_text": [
        22,
        20,
        35
      ],
      "icons": [
        62,
        41,
        118
      ],
      "icons_attention": [
        152,
        113,
        255
      ],
      "toolbar_top_separator": [
        0,
        0,
        0,
        0
      ],
      "toolbar_bottom_separator": [
        212,
        193,
        255
      ],
      "toolbar_vertical_separator": [
        212,
        193,
        255
      ],
      "tab_selected": [
        255,
        255,
        255
      ],
      "tab_text": [
        22,
        20,
        35
      ],
      "tab_background_text": [
        22,
        20,
        35
      ],
      "tab_line": [
        184,
        156,
        255
      ],
      "tab_loading": [
        184,
        156,
        255
      ],
      "tab_background_separator": [
        0,
        0,
        0,
        0.16
      ],
      "toolbar_field": [
        255,
        255,
        255
      ],
      "toolbar_field_text": [
        22,
        20,
        35
      ],
      "toolbar_field_border": [
        0,
        0,
        0,
        0.14
      ],
      "toolbar_field_focus": [
        255,
        255,
        255
      ],
      "toolbar_field_text_focus": [
        22,
        20,
        35
      ],
      "toolbar_field_separator": [
        0,
        0,
        0,
        0.16
      ],
      "sidebar": [
        255,
        255,
        255
      ],
      "sidebar_text": [
        22,
        20,
        35
      ],
      "sidebar_border": [
        212,
        193,
        255
      ],
      "sidebar_highlight": [
        234,
        221,
        255
      ],
      "button_background_hover": [
        234,
        221,
        255
      ],
      "button_background_active": [
        212,
        193,
        255
      ],
      "ntp_background": [
        245,
        236,
        255
      ]
    },
    "images": {
      "additional_backgrounds": [
        {
          "linear-gradient": "135deg, #F5ECFF 0%, #EADDFF 60%, #D4C1FF 100%"
        }
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ],
      "additional_backgrounds_size": [
        "auto"
      ]
    }
  },
  "dark_theme": {
    "colors": {
      "frame": [
        22,
        20,
        35
      ],
      "frame_inactive": [
        9,
        7,
        21
      ],
      "toolbar": [
        29,
        27,
        31
      ],
      "toolbar_text": [
        245,
        236,
        255
      ],
      "icons": [
        245,
        236,
        255
      ],
      "icons_attention": [
        184,
        156,
        255
      ],
      "toolbar_bottom_separator": [
        39,
        28,
        72
      ],
      "toolbar_vertical_separator": [
        39,
        28,
        72
      ],
      "tab_selected": [
        29,
        27,
        31
      ],
      "tab_text": [
        245,
        236,
        255
      ],
      "tab_background_text": [
        245,
        236,
        255
      ],
      "tab_line": [
        89,
        57,
        168
      ],
      "tab_loading": [
        89,
        57,
        168
      ],
      "toolbar_field": [
        29,
        27,
        31
      ],
      "toolbar_field_text": [
        245,
        236,
        255
      ],
      "toolbar_field_border": [
        63,
        62,
        66
      ],
      "toolbar_field_focus": [
        39,
        36,
        41
      ],
      "toolbar_field_text_focus": [
        245,
        236,
        255
      ],
      "sidebar": [
        29,
        27,
        31
      ],
      "sidebar_text": [
        245,
        236,
        255
      ],
      "sidebar_border": [
        39,
        28,
        72
      ],
      "sidebar_highlight": [
        89,
        57,
        168
      ],
      "button_background_hover": [
        89,
        57,
        168
      ],
      "button_background_active": [
        118,
        78,
        221
      ],
      "ntp_background": [
        22,
        20,
        35
      ]
    },
    "images": {
      "additional_backgrounds": [
        {
          "linear-gradient": "135deg, #3E2976 0%, #271C48 60%, #161423 100%"
        }
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ],
      "additional_backgrounds_size": [
        "auto"
      ]
    }
  }
}