OK sorry to keep asking advise but if someone could answer the following question I would appreciate it.

Question
Is it normal for the crankshaft to be discoloured at the blades next to the big-end bearings, the only way that I can describe it is that they have got a bluey black colouring to them, the same effect that you would get if you tempered a piece of metal i.e.: when you heat it then dip it in water.

I have done a search to see if I could find any photos to compare it with to see if it was normal but could not find anything