What is the most efficient way to paint a 3D Sculpture? Hello Everyone,

I am new to Blender and digital sculpting, I've only been at this a month or so. Thus far I've been unable to find a good resource regarding painting digital sculpts that will be used for illustrative purposes. Therefore I do not wish to make low-poly versions. Attached are a few busts I've created of some of my characters ranging from caricature, fantasy as well as cartoon. I'm looking for an efficient way to paint these for rendering in Cycles. Does anyone have any recommendations as to best-practices for painting high-poly sculpts that will be used for digital illustration and not gaming? Is there a some additional software I could get for this purpose? 

Thank you in advance for your help!
Best regards,
David Mansch
www.mansch.com
Use Vertex Paint mode to color the sculpt. To make the vertex colors renderable set the nodes as pictured below (add the Atribute node with the vertex color's name and use it as a Diffuse color). There are some limitations in this method though- you have the access to only few brushes (compared to the ones available in Texture Paint mode) and the sculpted mesh should be very dense if you want to paint some detailed strokes.