

The mouse cursor will change to a circle, the Tool Settings toolbar will appear (can be toggled from View » Tool Settings), and the object to be painted will render a uniform grey. In the main 3D Viewport switch the Viewport Shading mode to Solid then from the interaction mode menu ( Ctrl + Tab » 8) set Vertex Paint as the active mode. Painting vertex colours to a mesh is relatively straight forward.

Depending on where the mesh is then used the vertex colouring will modify the objects appearance without unduly taxing the rendering system. Here, objects can be tinted by painting colour or tonal information to the mesh in Vertex Paint mode. A cost effective way to change the appearance of an object that’s already UV mapped with a Diffuse (Base Color) image is to use Vertex Color.
