Examine source code of PaperColor

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "PaperColor",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-001-9c6d74e14860e77ee6f8f43e824bff25.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(238, 238, 238)",
      "toolbar_text": "rgb(0, 95, 135)",
      "frame": "rgb(0, 95, 135)",
      "tab_background_text": "rgb(238, 238, 238)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(68, 68, 68)",
      "tab_line": "rgb(0, 95, 135)",
      "popup": "rgb(238, 238, 238)",
      "popup_text": "rgb(68, 68, 68)",
      "button_background_active": "rgb(188, 188, 188)",
      "button_background_hover": "rgb(188, 188, 188)",
      "popup_border": "rgb(0, 95, 135)",
      "popup_highlight_text": "rgb(238, 238, 238)",
      "popup_highlight": "rgb(238, 238, 238)",
      "sidebar_border": "rgb(0, 95, 135)",
      "sidebar_highlight_text": "rgb(68, 68, 68)",
      "sidebar_highlight": "rgb(0, 95, 135)",
      "sidebar_text": "rgb(238, 238, 238)",
      "sidebar": "rgb(0, 95, 135)",
      "tab_loading": "rgb(0, 95, 135)"
    }
  }
}