Nardo and Catalunya are RS only colours.
Ara blue is a new Audi colour and can only be selected on some new S/RS models, not A.
A lot of other manufacturers are bringing out the Nardo look which makes the colour a little more common overall but you rarely see it on Audi RS's. You rarely see Audi RS's full stop.
Nardo and Alu is wrong, there are far better options and contrasts, it's not bad, it's just why would you when there are othe options.
I get the fact that it's free and people would rather spend the money on other options though. It is a shi*ter having to fork out £775 for a paint colour (Ara/Panther).
Nardo and black pack with the black gloss wheels, privacy and roof looks nice.