Importing SketchUp Models without textures and applying my own.

I am trying to import an un-textured model from sketchup into unity and apply my own materials to the model. However, when i try to apply one of my materials to a component of the imported Sketchup folder the material does not render. Instead it just takes a colour that looks like the material and applies that. In inspector it says the material is applied. Is there a way to apply materials to sketchup models or does Blender need to be used?