I have been experimenting fot the first time with Blue Barn presets and have been looking for a lovely warm exagerated colour which we have been acustomed to on our TV sets.

Why is it that I seem to get the best result when the XL2 is set to the "Ext Cont" position while recording? I was using the Amelie preset but this looks different and not so colourful when the camera is set to the TV mode.

Ext. Cont. is the external control mode for controlling the camera remotely, for instance via the Console software from a laptop computer. Ext. Cont. is not a program mode. The difference you're seeing in the image is not related to the Ext. Cont. mode. Try experimenting with the program modes A, Av, Tv and M and observe the differences in each.