Examine source code of Summertime '21

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Tropical",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-001-9c6d74e14860e77ee6f8f43e824bff25.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 183, 255, 0.38)",
      "toolbar_text": "rgb(5, 124, 167)",
      "frame": "rgb(221, 249, 118)",
      "tab_background_text": "rgb(38, 124, 154)",
      "toolbar_field": "rgba(221, 249, 118, 0.48)",
      "toolbar_field_text": "rgb(38, 124, 154)",
      "tab_line": "rgb(0, 183, 255)",
      "popup": "rgba(221, 249, 118, 0.72)",
      "popup_text": "rgb(5, 124, 167)",
      "toolbar_top_separator": "rgb(157, 168, 173)",
      "tab_loading": "rgb(0, 183, 255)"
    }
  }
}