Thanks everyone, they are definitely black. The engine has gone back to the owner, too much time spent on it and not prepared to spend more.

Have to agree with you, but was hoping for a more easy option. Most strange that the wiring diagram for this model does not appear anywhere. 

Thanks for your prompt response, this is the only printout that I have been able to find. The wiring diagram bears no resemblance to the one in this engine. All the wires in the download are coloured, the wiring in the engine I have are mainly black.

This is a long shot, but does anyone have a wiring diagram for this engine that they could share with me, I have tried to locate one through many channels and this forum is my last resort, my intention is to fit a basic loco decoder. it is supposed to be DCC ready but there is literally nowhere to plug in a decoder, majority of the wiring is plain black, which doesn't help.
The engine was purchased 2nd hand with no manuals
Any help would be appreciated.
It runs well on DC current.