Examine source code of Calm Blue Day

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Bright Blue Day",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-012-1e971c5fbb8dec3acbd76dd6c6819de9.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(27, 85, 191)",
      "toolbar_text": "rgb(255, 228, 85)",
      "frame": "rgb(71, 169, 229)",
      "tab_background_text": "rgb(255, 213, 115)",
      "toolbar_field": "rgb(242, 230, 132)",
      "toolbar_field_text": "rgb(96, 166, 249)",
      "tab_line": "rgb(255, 223, 60)",
      "popup": "rgb(247, 244, 127)",
      "popup_text": "rgb(202, 108, 48)",
      "tab_loading": "rgb(255, 223, 60)"
    }
  }
}