Examine source code of Cool theme with \

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Cool theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-001-9c6d74e14860e77ee6f8f43e824bff25.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(96, 100, 101, 0.71)",
      "toolbar_text": "rgb(149, 135, 167)",
      "frame": "rgb(142, 179, 201)",
      "tab_background_text": "rgb(65, 65, 70)",
      "toolbar_field": "rgba(74, 71, 71, 0.57)",
      "toolbar_field_text": "rgb(250, 250, 254)",
      "tab_line": "rgb(248, 112, 140)",
      "popup": "rgb(71, 71, 75)",
      "popup_text": "rgb(248, 248, 251)",
      "tab_loading": "rgb(248, 112, 140)"
    }
  }
}