Coloring polygons using
color per vertex data
In addition to assigning shaders to your polygon meshes, you can also assign a color to each vertex associated with a polygon face. Color per vertex data (CPV) is commonly applied to 3D models that are created for interactive video games to more efficiently simulate shading and prelighting effects.
Color per vertex data can be assigned even when a polygon vertex is shared between faces, it has a color for each face that shares it. The colors at the vertices of a face are blended together across the face.
Color per vertex data gets stored separately in the maya scene file when it is saved. You can also apply one or more sets of CPV data (called color sets) to a polygon mesh.