[muso]

I bought him as a black and tan, his parents both are red/tan with rich dark colours, but he started to develop grey coat along the top of his back but the saddles are still black, I am hoping he doesn't lose the black/red and tan colouring.

I have seen lots of black and tans with the 'stripe' of grey along the back, he is 6 months old at the time of the photo.
There is nothing wrong with Sables but I bought him as a black and tan because that's what I wanted, I think he will be a black and red with lots of grey through the neck and along the back.