Using Vertex Colors

Vertex color, or vcolor, is just a color with RGB and alpha channel values stored for each vertex of a mesh. Vertex color and alpha can be used for multi-texturing, transparency, or fake ambient occlusion.

Vertex color is typically multiplied against the Diffuse color, colorizing or darkening the color map.

When used for non-color effects, typically each color channel is treated as a separate monochrome set of values, so for example vertex color can control three different per-vertex effects.

Vertex Colors is a Shader Generation parameter that can be enabled using the Material Editor, which is part of Lumberyard Editor.

For a good application of vertex colors, see Defining Vegetation Vertex Colors with a DCC Tool.