Examine source code of Matte_Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Matte Dark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-027-1049af643fc55b4ffd4a8575444547c5.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(77, 77, 77)",
      "toolbar_text": "rgb(216, 216, 216)",
      "frame": "rgb(56, 58, 58)",
      "tab_background_text": "rgb(195, 195, 195)",
      "toolbar_field": "rgb(225, 228, 228)",
      "toolbar_field_text": "rgb(31, 32, 32)",
      "tab_line": "rgb(12, 88, 175)",
      "popup": "rgb(77, 77, 77)",
      "popup_text": "rgb(195, 195, 195)",
      "tab_loading": "rgb(12, 88, 175)"
    }
  }
}