Any way to invert greys given by AMBIENT OCCLUSION?

[micheus]

I'm not sure I understood your question...
- If you are talking about use a different colour to the white one, then just change the Ambient light color;
- If that "invert grays" means swap the white and black, I think the only way is using a external program;
- if you want mix the OC and objects colours, then I think you can put some colour in your object, UV map it using the option vertex color when creating the texture - make it external. Then, apply OC and create the texture again. You can make it external using another name and mix them using PS or Gimp. Or, if you want only see the textured colour and OC overlapped in the screen you just need to change colored texture material and set the Vertex Color to Multiply.