Examine source code of blueriver

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "blueriver",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-010-e9f94a3e61666a4c7677eb9cce17d854.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(42, 60, 81)",
      "toolbar_text": "rgb(255, 234, 209)",
      "frame": "rgb(51, 72, 98)",
      "tab_background_text": "rgb(255, 238, 220)",
      "toolbar_field": "rgb(51, 72, 98)",
      "toolbar_field_text": "rgb(255, 239, 221)",
      "tab_line": "rgb(121, 164, 211)",
      "popup": "rgb(51, 72, 98)",
      "popup_text": "rgb(247, 234, 220)",
      "tab_loading": "rgb(121, 164, 211)"
    }
  }
}