Examine source code of sombre

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "black is black",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-009-f069b97f439938a011297c84464f0df6.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(42, 42, 46)",
      "toolbar_text": "rgb(116, 116, 116)",
      "frame": "rgb(28, 27, 33)",
      "tab_background_text": "rgb(172, 172, 172)",
      "toolbar_field": "rgb(28, 27, 33)",
      "toolbar_field_text": "rgb(169, 169, 169)",
      "tab_line": "rgb(28, 27, 33)",
      "popup": "rgb(56, 56, 61)",
      "popup_text": "rgb(169, 169, 169)",
      "button_background_hover": "rgb(28, 27, 33)",
      "frame_inactive": "rgb(42, 42, 46)",
      "icons": "rgb(169, 169, 169)",
      "ntp_background": "rgb(234, 234, 234)",
      "popup_border": "rgb(56, 56, 61)",
      "tab_text": "rgb(132, 132, 132)",
      "toolbar_field_border": "rgb(56, 56, 61)",
      "toolbar_top_separator": "rgb(56, 56, 61)",
      "tab_loading": "rgb(28, 27, 33)"
    }
  }
}