Examine source code of Minecraft Grass Block

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "minecraft MOJANG ",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat-y"
      ]
    },
    "colors": {
      "toolbar": "rgba(250, 245, 245, 0.16)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(19, 100, 7)",
      "tab_background_text": "rgb(250, 245, 245)",
      "toolbar_field": "rgba(12, 46, 243, 0.5)",
      "toolbar_field_text": "rgb(250, 245, 245)",
      "tab_line": "rgb(143, 254, 5)",
      "popup": "rgba(5, 8, 254, 0.48)",
      "popup_text": "rgb(0, 0, 0)",
      "ntp_background": "rgb(29, 219, 155)",
      "tab_loading": "rgb(143, 254, 5)"
    }
  }
}