The SRT has always had like zero interior color options, the all slate-grey interior is supposed to be the SRT-specific. It comes from what the SRT was originally supposed to be, that is, a trim package in and of itself.
I agree that the Overland Interior is by far nicer and has more options, and without getting into the price debate, again, the SRT takes second place.
But if they're going to justify the much higher market demographic in the futre, they're going to have to dump the 'SRT trim' attitude to satisfy their new clients, who want the same options the bimmer and benz guys have, which is to mix and match their own high-end creations.