read:getBandedRanges

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Payload",
  "type": "object",
  "properties": {
    "sheet": {
      "type": "string"
    }
  },
  "required": [
    "sheet"
  ]
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Output",
  "type": "object",
  "properties": {
    "bandedRanges": {
      "description": "Every banded range on `sheet`, in real precedence order.",
      "type": "array",
      "items": {
        "$ref": "#/$defs/BandedRangeInfo"
      }
    }
  },
  "required": [
    "bandedRanges"
  ],
  "$defs": {
    "BandedRangeInfo": {
      "description": "One banded range's identity, target rectangle, and style.",
      "type": "object",
      "properties": {
        "id": {
          "type": "string"
        },
        "range": {
          "$ref": "#/$defs/CellRange"
        },
        "style": {
          "$ref": "#/$defs/StyleOut"
        }
      },
      "required": [
        "id",
        "range",
        "style"
      ]
    },
    "CellRange": {
      "description": "An inclusive rectangle. `from`/`to` may be equal, a single cell.",
      "type": "object",
      "properties": {
        "from": {
          "description": "Top-left cell, e.g. `\"A1\"`.",
          "type": "string"
        },
        "to": {
          "description": "Bottom-right cell, e.g. `\"B3\"`.",
          "type": "string"
        }
      },
      "required": [
        "from",
        "to"
      ]
    },
    "StyleOut": {
      "description": "A banded range's color assignment, as reported back by this command.",
      "type": "object",
      "properties": {
        "headerColor": {
          "anyOf": [
            {
              "$ref": "#/$defs/HexColor"
            },
            {
              "type": "null"
            }
          ]
        },
        "firstBandColor": {
          "$ref": "#/$defs/HexColor"
        },
        "secondBandColor": {
          "$ref": "#/$defs/HexColor"
        },
        "footerColor": {
          "anyOf": [
            {
              "$ref": "#/$defs/HexColor"
            },
            {
              "type": "null"
            }
          ]
        }
      },
      "required": [
        "firstBandColor",
        "secondBandColor"
      ]
    },
    "HexColor": {
      "description": "A strictly-validated `#rgb`/`#rrggbb`/`#rrggbbaa` hex colour.",
      "type": "string"
    }
  }
}