One of my favorite buildings I've ever visited is the Opera Garnier in Paris. The building was designed by Charles Garnier under the reign of Napoleon III. Two of the lesser known rooms in the structure, but in my opinion are the most spectacular, are two small rotundas dedicated to the sun and moon.
The Salon of the Sun has two mythological dragons in the center medallion with a massive sun burst filling the dome. All the details have a goldish tint so that the entire room glows. Even the infinity mirrors which reflect across the room have a gold tint to the glass.
The Salon of the Moon has a series of bats in the medallion with silver moon rays and gilded stars on the dome. The details are picked out in silver-leaf instead of gold and the mirrors have a bluer tint to them.
All of the rooms of the Opera Garnier are over the top... but these rooms are perfection... they're just enough and the subtle detailing provides a break from the riotous marble, statuary, and gilding of the other rooms of the opera house... the scale of these rooms is also more human... I'd love to make one of these rooms my bedroom...