Vertex Color Toolkit is an add-on that enables users to edit vertex colors directly in Blender's edit mode by utilizing mesh selections rather than traditional brush painting. It is designed to help store arbitrary data within vertex colors for export to game engines. The tool allows for targeted painting on individual color channels, including the alpha channel, mimicking workflows found in engines like Unreal.

The add-on includes a system for creating and managing custom color palettes that function in both edit mode and vertex paint mode. It also features configurable keyboard shortcuts for core actions and includes a utility to preview vertex colors directly within the Solid Viewport Shading mode.