Have a look at a useful new tool for 3DS Max.
Joker Martini has recently released a new plugin for 3ds Max that lets you apply vertex colors based on different conditions. You can set vertex colors by Object, Element, and Vertex using distance, position, selection order, names, or use randomness.
You can also reverse the sorting order, group sorting objects, or individually set vertex colors for the RGBA channels.
The tool is now available for $3. You can learn more and get it here.