Examine source code of Black color contrast

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Black color contrast",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-030-0f935cfde055600d01a959c5c15353de.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(0, 0, 0)",
      "toolbar_text": "rgb(255, 127, 21)",
      "frame": "rgb(22, 21, 21)",
      "tab_background_text": "rgb(52, 245, 233)",
      "toolbar_field": "rgb(7, 7, 7)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(58, 249, 98)",
      "popup": "rgb(16, 17, 17)",
      "popup_text": "rgb(252, 252, 252)",
      "icons": "rgb(255, 232, 57)",
      "ntp_background": "rgb(0, 0, 0)",
      "tab_loading": "rgb(58, 249, 98)"
    }
  }
}