How to turn off textures in Blender Internal render? Actually I know that there is an appropriate option in render tab in Shading rollout. But it seems to work only with usual materials, not node-based.

I want to make fast render without shading and textures just for the preview and can't figure how to disable textures in node-based materials.

Some sort of python script which mute all textures would be usefull.

EDIT: Added screenshot of set-up I have
Go to the Texture header and uncheck the desired texture slot checkboxes in material textures tab. Then render.