Thanks for the suggestion. I gave it a go and sadly everything is still solid blue!

Interestingly, I had a play around yesterday and changed the material to one of the default materials, and that changed the legend to show 0-1e8 cycles, and the graphic displayed correctly. It seems there's something funny going on with this material model, but I can't find any cause. 

I've no idea why it is showing 1e32 cycles maximum when I have set 1e8 as my limit in the material model and the program.