I realise its a different vehicle but the new software would all follow the same colour scheme. For example, my RX is on 2012 factory software and it still has the dark blue background.
Its possible that the software is new for the RX400h, but not "new new, if that makes sense.
There is no huge difference in characteristics of the 2nd Gen RX in the UK. Much like how there is no huge difference in ride quality between the IS300h and an IS200t, or an RX450h and an RX200t, or a GS300h and a GS450h.