'RhinoPaint3D is a free Rhino plugin allowing intuitive painting, as is performed with pixel images, but on multi-resolution mesh geometries. Painting can be done based on vertices or faces within a single mesh. Colorwheel, Eyedropper and Eraser functions are included in the plug-in.'
Link to 'RhinoPaint3D' post on UTO website
Link to 'RhinoPaint3D' on food4rhino website