Blender materials are limited to 16 per object.

If the material zones are critical you can circumvent this by using the separate by options in the import  object dialog. This does create other concerns depending on what you intend to do in Blender.

Collada import, while importing the skeleton and mesh, still requires a great deal of work and the methodology is different than Poser as weight painting of the blend zones is the primary technique used to control basic mesh deformation.

On to projection painting in Blender, this video tutorial cg.cgcookie.com/2009/06/18/projection-painting shows how to use the function.