Quick Start

This guide shows how to create and validate your first PaletteJSON file.

Minimal file

A minimal valid file contains at least one palette, with a name, slug, type, and two or more colours.

Bare Minimum

{
  "palettes": [
    {
      "name": "Example",
      "slug": "example",
      "type": "categorical",
      "colors": [{ "hex": "#FFFFFF" }, { "hex": "#000000" }]
    }
  ]
}

• name — human-readable label for the palette.
• slug — URL-safe identifier (lowercase letters, numbers, hyphens).
• type — one of categorical, sequential, diverging.
• colors — array with at least two colours.

Colour values

Each colour can be defined with hex (#RRGGBB or #RRGGBBAA) or components (numeric array interpreted by a palette-level colorSpace).
If both are present, consumers should treat components as authoritative and use hex for preview/interoperability.

File identification

To make your file portable:

• Extension: .palette.json
• Encoding: UTF-8
• Media type: application/prs.palettejson+json (fall back to application/json if needed)
• Apple UTI (optional): org.palettejson.json.

note

These identifiers are recommendations for tooling and do not affect schema validity.

Validating a file

You can validate PaletteJSON against the official schema (palettejson.schema.json), which targets JSON Schema draft 2020-12.

Node.js (AJV v8)

// Install: npm i ajv
import Ajv from "ajv";
import addFormats from "ajv-formats";
import schema from "./palettejson.schema.json" assert { type: "json" };

// Example data
const data = {
  palettes: [
    {
      name: "Example",
      slug: "example",
      type: "categorical",
      colors: [{ hex: "#FFFFFF" }, { hex: "#000000" }],
    },
  ],
};

const ajv = new Ajv({ strict: false }); // strict off if you prefer fewer warnings
addFormats(ajv);

const validate = ajv.compile(schema);
const valid = validate(data);

if (valid) {
  console.log("Valid!");
} else {
  console.error("Validation errors:", validate.errors);
}

Python (jsonschema)

# Install: pip install jsonschema
import json
from jsonschema import validate, Draft202012Validator

# Load the schema file (placed next to this script)
with open("palettejson.schema.json", "r", encoding="utf-8") as f:
    schema = json.load(f)

# Example data
data = {
    "palettes": [
        {
            "name": "Example",
            "slug": "example",
            "type": "categorical",
            "colors": [{"hex": "#FFFFFF"}, {"hex": "#000000"}]
        }
    ]
}

# Optional: sanity-check the schema itself
Draft202012Validator.check_schema(schema)

# Validate
validate(instance=data, schema=schema)
print("Valid!")

Common gotchas (v0.1)

• If any colour in a palette uses components, the palette must declare colorSpace.
• If any colour has a position, all colours in that palette must have a position (1-based).
• hex is always interpreted as display sRGB; alpha (if present) is the last pair: #RRGGBBAA.
• Component ranges depend on colorSpace:
  • sRGB / DisplayP3: 3–4 numbers, each in [0, 1]
  • sRGB-linear-extended: either 3 numbers (unbounded) or 4 with alpha in [0, 1]
  • Lab: exactly 3 numbers; L in [0, 100] (a/b unbounded)
  • OKLCH: exactly 3 numbers; L in [0, 1], C ≥ 0, h ∈ [0, 360)

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Next steps

• Read the File Format and Palette specs for required/optional fields.
• See the Colour page for hex vs components, references, position, and legibility metadata.
• Explore Examples for richer use cases.