1. Create TWO new materials. Use color sliders to assign the color red to one, blue to the other. Name each material after the color. Assign the same texture image (I used the SketchUV default texture "texture_grid.png") to each. Tick the "colorize" box.
http://i.imgur.com/XaxDTel.png

2. Apply each material a box using triple click to apply to all surfaces.
http://i.imgur.com/2W0ddEY.png

3. Export model to Unity using PlayUp tools 21.0
http://i.imgur.com/9cY6Bx9.png

4. Unity materials folder contains one material named "texture_grid" colored blue. The red material has not been exported because PlayUp tries to name both of them after the texture file ("texture_grid"), instead of the material name ("Blue" and "Red" in this case), and there is a name collision. http://i.imgur.com/JPFKEFl.png

5. Unity texture folder contains a colorized blue textured version of "texture_grid.png" named "texture_grid.tga", but no read texture for the same reason as 5 above. http://i.imgur.com/VS1CTnA.png

6. Solution: PlayUp texture exporter should name colorized textures and materials after the unique Sketchup Material name, not the Texture Image.

Playup is pretty darn cool. Well done. I am using it to try and import a pretty tasty size architectural project into unity. I have a couple of stumbling blocks:
1. UV coords on PlayUp objects.
In unity, I cannot bake using the lightmapper as every playup object reports a UV error. If not every, an awful lot of them!

2. Materials.
I'm sensing this maybe related, but on some objects, the materials do not show. I know the normals are ok...I'm guessing its related to the UV coords. No matter what material I apply to these objects, they don't render - presumably because the UV mapped is misisng or messed up.

3. I don't really understand your LOD system. It feels like it could be awesome! Let's say I have 100 doors in my model...and their polygon count is choking Unity. What would be way cool is to have ONE instance of a low poly version and somehow tell Playup to replace all 100 doors with that one low poly version (applying xform and scale) as its exporting. Right now, I ***think*** I need to create a 100 low poly doors and position them and then instruct PlayUp? Or maybe I'm just dumb and misunderstanding the whole system!

So I've built a model with 197 different components, however when I export as a level, some of the components spawn in reandom locations. For example, in the building I exported the wall is made of four different components, yet those components appear rotated on both the Z and X-axis. This also goes for the windows on that wall, but one half of the windows (french-door type) will stay in the correct position while the other half is rotated and moved randomly, but also the decorative supports of the window that was rotated will stay in the correct position but will have been rotated 90 degrees.

This is really a fantastic tool, and it works great with sketchup. I especially like the level export feature to export very complex objects to Unity. However, in the process components often are not recognized as being the same size and for each size a new object is created (e.g. object_99_100_100). I don't know whether this really is a bug or a desired result, but would it not be possible to create exactly one object per component definition and apply the scale in Unity? If not, then is there at least a possibility that the scaling gets detected correctly, if the object is not scaled in Sketchup?