It's no different in concept than painting an accent wall a different color. It creates visual interest. I like the paint color they chose to coordinate with the tile. I would have put the toilet seat down before photographing it, though. :-)

For the record, we have had a counter top over the toilet for 20 years with no problem. There was a cutout at the top to allow access the to toilet tank (I put a tissue box in it). For our new bathroom coming up next month, I am having a granite top made and will again extend it over the toilet...this time with no cutout. To allow for access to the toilet, we are going to install a new, low profile, toilet. I like the extra counter space, very handy! I don't think it looks dated at all.

I vote minera to provide contrast. Does this darker color pick up the darker veining in your marble? I think that would be very pretty. I also like the minera and the nougat together in your photo. I see that it is hard to photograph the minera. It also looks like a soft dark color and not harsh. I definitely don't like the photo above this post with the dark modern cabinets.

Got these selections off of Houzz, maybe you've seen them already. This pic has a wood frame holding the counter over the toilet. Maybe an opportunity for a small tip out tray to hold TP, like the tip out trays that I've seen at kitchen sinks: [Tropical Bathroom[(https://www.houzz.com/photos/tropical-bathroom-ideas-phbr1-bp~t_712~s_2108) by Sarasota General Contractors Dynan Construction Management [Contemporary Bathroom[(https://www.houzz.com/photos/contemporary-bathroom-ideas-phbr1-bp~t_712~s_2103) by New York Architects & Designers Tobin + Parnes Design Enterprises [Eclectic Bathroom[(https://www.houzz.com/photos/eclectic-bathroom-ideas-phbr1-bp~t_712~s_2104) by Naples Interior Designers & Decorators Nichole Claprood w/ Reed Design Build LLC [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107)