Accessibility

PaletteJSON allows palettes to include an accessibility object.
This metadata records testing and notes related to color-vision deficiency (CVD) and perceptual distinctiveness.

Properties

cvdTestedFor (optional)

• Type: array of strings
• Allowed values: protanopia, deuteranopia, tritanopia, achromatopsia

Purpose: declare which color-vision deficiencies have been explicitly tested for this palette.

cvdMaxDistinctClasses (optional)

• Type: object
• Keys: freeform labels (e.g. protanopia, overall)
• Values: integers ≥ 1

Purpose: indicate the maximum number of classes (distinct colors) that remain distinguishable under a given CVD condition.

Example:

"cvdMaxDistinctClasses": {
  "overall": 6,
  "protanopia": 5
}

tools (optional)

• Type: array of strings
• Purpose: list tools or simulators used for accessibility testing.

notes (optional)

• Type: string
• Freeform commentary about testing or limitations.

Examples

{
  "name": "Accessible Palette",
  "slug": "accessible",
  "type": "categorical",
  "colors": [{ "hex": "#1F77B4" }, { "hex": "#FF7F0E" }, { "hex": "#2CA02C" }],
  "accessibility": {
    "cvdTestedFor": ["protanopia", "deuteranopia"],
    "cvdMaxDistinctClasses": {
      "overall": 6,
      "protanopia": 5
    },
    "tools": ["Sim Daltonism", "Coblis"],
    "notes": "Distinctness verified for deuteranopia, some merging under protanopia."
  }
}

Usage guidance

• Keep cvdTestedFor to the conditions you actually checked.
• Use cvdMaxDistinctClasses to give consumers an idea of safe usage limits.
• List the actual tools used for reproducibility.
• Add notes for nuances or caveats.