Sacré Coeur's backside is black and grimy and I wouldn't want it any other way. A bit of gothic gloom didn't do anyone any harm.
Unfortunately, perhaps, Paris is in the process of effectively culling centuries of accumulated crud in the name of cheering the place up a bit I guess.
Result: Notre Dame now sparkles; the Tour Saint-Jacques fairly blinds; and the once sinister towers of the Conciergerie, newly revealed from beneath their palace-sized Sumsung and L'Oréal ads now veritably glisten in the sly summer sun. Even the Sainte-Chapelle's currently under wraps - it seems no murky mediaeval ediface is safe from the vicious sand blaster, blast it!
None save Sacré Coeur, which isn't mediaeval at all of course. The front's pristine, certainly, but wander around the back and you'll see the true meaning of grime, and that after only a century or so - lovely.
The Conciergerie's now so white it disconcerts those who are used to its habitual darkness. It also makes the neighbouring buildings, like the Seine side of the Hôtel de Dieu, look filthy!
The one thing I am excited about is the revealing of the Tour de l'Horloge's renovated first Paris public clock. From what I can glimpse through the coverings it looks splendid. And as for the Conciergerie, I'll try not to lose my head about it.