Some came with the blue coolant from the factory (mine did) - this just needs changing more regularly than the orange coolant (which they claim should last 10 years IIRC)

So it shouldn't matter which one you use, but it's probably wise not to mix them as mentioned above. I replaced my blue coolant with orange when I changed my thermostat, as I don't think it was much more expensive.

You will need to drain out the system, and thoroughly flush it through to remove any traces of coolant.

The two types cannot be mixed, the chemical composition is different. The 'red coolant' is much better than the blue, and has a longer life span.

The RAC man should really have known better than to put 'blue coolant ' in your engine.

I would be conducting an investigation, to find out why there is no coolant in the engine?

This suggests a bad leak somewhere.