Vertex colours

A vertex colour is a colour value stored directly on a mesh's vertices instead of in a texture. Blender's manual: "Color data can be applied directly to an object's vertices rather than using a texture or a material" (Blender 3.6 Manual: Object Data Properties). Unity lists it among the optional data a mesh can carry per vertex (Unity Manual 2022.2: Anatomy of a mesh).

In games, vertex colour is mostly not seen as colour. It is a cheap per-vertex mask that a shader reads to decide where moss grows, where paint is chipped, or which of two materials shows. See vertex painting and blending.

Two wall strips: raw red vertex colours on the left, and the same values used as a stone-to-moss blend mask on the right. — Left: raw vertex colours stored per vertex (red channel strongest at the bottom). Right: a material using that red channel as a mask between stone and moss. Values are interpolated between vertices, so the mesh density (here a 16 × 8 grid) limits how sharp the blend can be.Rendered in Blender 5.2 (Cycles) by the handbook author

#How it is stored

Each vertex gets a red, green, blue and usually alpha value, and the GPU blends smoothly between vertices across each triangle. glTF says vertex colour values "are interpolated across topology primitives" (Khronos Group: glTF 2.0 Specification).

Blender stores colour as Color Attributes with two choices (Blender 3.6 Manual: Object Data Properties):

Domain: Vertex (one colour per vertex) or Face Corner (one per corner of each face, so adjacent faces can differ).
Data type: Color, "RGBA color with floating-point precision", or Byte Color, "RGBA color with 8-bit precision".

A real-time mesh can hold only one value per attribute per vertex. As one Polycount poster put it, "A single vert can only have one normal and one UV coordinate" (Polycount forum: Vertex Count vs Triangle Count), and per-face colour changes split vertices for the same reason (Polycount forum: Vertex Count vs Triangle Count). Hard colour edges cost extra vertices.

#Common uses

Use	Example	Related page
Material blending	Up to four layers blended by vertex alpha on The Order: 1886 (Neubelt & Dawn) 2013)	vertex painting and blending, material layers and Substrate, height blending
Wear, moss and grime	Moss, damage, efflorescence and mould on Naughty Dog's dam walls (ArtStation)	edge wear, detail maps and macro variation
Visible colour or tint	Godot can use vertex colour as albedo (Godot Engine); glTF multiplies it with base colour (Khronos Group)	base colour (albedo) map
Baking IDs	Substance's bakers can use vertex colour to build ID maps (Substance 3D Bakers documentation)	baking

#Colour space

Vertex colours raise the same question as textures: are the numbers sRGB or linear? See colour space: sRGB and linear.

glTF: COLOR_0 values "are encoded with the linear transfer function, i.e., their values are used as-is", and they multiply the material's base colour (Khronos Group: glTF 2.0 Specification). Components must be in the 0 to 1 range (Khronos Group: glTF 2.0 Specification).
Godot: vertex colours are treated as linear by default; the vertex_color_is_srgb option converts them from sRGB when needed (Godot Engine: BaseMaterial3D). To use them as colour at all, enable vertex_color_use_as_albedo (Godot Engine: BaseMaterial3D).

Different viewsVertex colour or mask texture?

Vertex colour is nearly free. It uses no texture memory and no extra texture sample, and painting works directly on the mesh. Ready at Dawn and Naughty Dog both use it to break up tiling materials at scale (Neubelt & Dawn) 2013; ArtStation: Brick and Concrete Generator).

Resolution depends on the mesh. Because values are interpolated between vertices (Khronos Group: glTF 2.0 Specification), a low-poly wall gives only soft, blobby masks; sharp detail needs extra edges, which split vertices where colours change abruptly (Polycount forum: Vertex Count vs Triangle Count).

In practice: use vertex colour for broad, soft variation on dense-enough meshes, combined with height blending to sharpen the transitions. Use a mask texture when the pattern needs crisp detail or the mesh is very low-poly.

#Common mistakes

Too few vertices to paint on. Add a few edge loops where blends should happen.
Lost on export. Check that your exporter writes the colour set you painted. Blender 4.5 added a glTF export option for named vertex colours (Blender Developer Documentation: Blender 4.5 LTS: Pipeline & I/O).
Wrong colour space. A mask that looks too strong or too weak may be read as sRGB in one tool and linear in another (Khronos Group: glTF 2.0 Specification; Godot Engine: BaseMaterial3D).
Default white or black. An unpainted mesh may import with all channels at 1 or 0, so every blend is fully on or off.

#Further reading and watching

Brick and Concrete Generator (Jared Sobotta)

six vertex colour channels driving moss, damage and mould on The Last of Us Part I. Intermediate, free.

BreakdownIntermediateFree

Blender Manual: Color Attributes

domains, data types and painting modes. Beginner, free.

DocsBeginnerFree

glTF 2.0 Specification (Khronos)

how COLOR_0 is stored and used. Advanced, free.

WebAdvancedFree

References

Blender Foundation · Object Data Properties (Color Attributes) · Blender 3.6 Manual, 2023 · docs · accessed 2026-10-21

Unity Technologies · Anatomy of a mesh · Unity Manual 2022.2, 2022 · docs · accessed 2026-10-20

Khronos Group · glTF 2.0 Specification · Khronos Group (GitHub) · docs · accessed 2026-10-21

Vertex Count vs Triangle Count · Polycount forum, 2014 · forum · accessed 2026-10-20

Jared Sobotta · Brick and Concrete Generator · ArtStation, 2023 · article · accessed 2026-10-21

David Neubelt and Matt Pettineo (Ready at Dawn) · Crafting a Next-Gen Material Pipeline for The Order: 1886 · SIGGRAPH 2013 Physically Based Shading course notes, 2013 · paper · accessed 2026-10-21

Godot Engine contributors · BaseMaterial3D (class reference source) · Godot Engine (GitHub), 2026 · docs · accessed 2026-10-21

Adobe · Color Map from Mesh · Substance 3D Bakers documentation · docs · accessed 2026-10-21

Blender Foundation · Blender 4.5 LTS: Pipeline & I/O · Blender Developer Documentation (release notes), 2025 · docs · accessed 2026-10-20