Hi jack worswick.
I think you have been unlucky – I ordered my ultimate -misty jungle -light interior – on 28th October and got the car end of July – so 9 months.
We can only guess what the build criterion was / is in terms of spec colour and interior – the only thing I think is quite certain is the premium orders tended to be dispatched before ultimate (far fewer chips).
As many of us have said the ultimate is a lovely car and is worth the wait –
Hopefully you will get your car sooner rather than later.