My current MKX is ingot silver and I see where the new silver is called radiant silver. Wonder if its much of a difference. I'm also with you on the slate interior. That is the only interior color I will consider. Glad it is still available although you cannot find many on the lot with it.
I have been looking for the 2020 order guide as well. I did find however the 2020 Nautilus fleet brochure and it shows a few exterior color changes along with what I thought was interesting was a exterior shot of the car with the Nautilus badging missing from the door. I don't know if this was intentional or a mistake. If they remove the door badging I guess they will move the Nautilus name to the rear lift gate.