Well after playing around i decided to totally get rid of the 'red view' and by accident found out that the toon shader does not just colour everything in the selected colour, but if you put low values into the RGB floats it kinda... magnifies the colours. so ive kept thermal view and just alter the light values to blue and set my character models to UNLIT and this is the end result:

Normal View



Thermal View



Needs tweaking a little more. As you can see its based around the Predator. not for a commercial project but an experiment to see just how close to the original movies you can go when your not working for a big company (which is why i really wanted to keep the blue thermal background as it looks very much like the original as opposed to just changing fog colours, textures etc)