COLR table

Defines multi-colored glyphs using layered glyph references (v0) or a full paint graph (v1).

Scope

• Format family: Shared SFNT
• Table tag in JSON: COLR

Specs

• https://learn.microsoft.com/en-us/typography/opentype/spec/colr
• OpenType table registry: https://learn.microsoft.com/en-us/typography/opentype/spec/otff#font-tables

JSON Skeleton

This skeleton reflects fields currently parsed/written by Font Flux JS for this table.

{
  "tables": {
    "COLR": {
      "baseGlyphRecords": null,
      "layerRecords": null,
      "version": 0,
      "baseGlyphPaintRecords": null,
      "layerPaints": null,
      "clipList": null,
      "varIndexMap": null,
      "itemVariationStore": null,
      "_checksum": 0
    }
  }
}

Top-level Fields

• baseGlyphRecords - implementation-defined
• layerRecords - implementation-defined
• version - number (0..65535) [spec type: uint16] (0)
• baseGlyphPaintRecords - implementation-defined
• layerPaints - implementation-defined
• clipList - implementation-defined
• varIndexMap - implementation-defined
• itemVariationStore - implementation-defined

Validation Constraints

• version = 0: use parsed baseGlyphRecords and layerRecords.
• version >= 1: this implementation preserves v1 paint graph data as _v1RawBytes for round-trip safety.
• For v0 data, each BaseGlyphRecord's firstLayerIndex/numLayers should reference valid ranges inside layerRecords.
• paletteIndex entries in layers should be valid for the active CPAL palette entry count.

Authoring Example

{
	"tables": {
		"COLR": {
			"version": 0,
			"baseGlyphRecords": [
				{ "glyphID": 100, "firstLayerIndex": 0, "numLayers": 2 }
			],
			"layerRecords": [
				{ "glyphID": 101, "paletteIndex": 0 },
				{ "glyphID": 102, "paletteIndex": 1 }
			],
			"_checksum": 0
		}
	}
}

Additional Nested Keys Seen In Implementation

• glyphID
• firstLayerIndex
• numLayers
• paletteIndex
• baseGlyphPaintRecords
• layerPaints
• clipList
• varIndexMap
• itemVariationStore

Notes

• Preserve _checksum for stable round-tripping.
• If a table is only partially understood, prefer keeping unknown bytes in _raw instead of dropping data.
• Validate with .validate() after edits.