Preview Vertex Colors

Switches viewport to Attribute color type to preview vertex colors changes. Toggling the button will return viewport's color type to previous user setting.

Mesh Similarity

Float value that controls dimension difference meshes could have to be combined into a single vertex color.
Higher - more different meshes are treated as same.

Use Random Seed

Ignore persistency and assign random values to similar meshes.

Check Across Selected

Checks submeshes across all selected meshes. If unchecked - checks selected objects' submeshes individually.