The short answer seems to be... surprisingly... oui!
But before we dive into this, the results of our mini-survey are back. And it's pretty clear that people prefer having the second day to work on the Challenge. So I'll shift to this plan for a while, see how it goes. Challenge on Wednesday, and then maybe commentary on what I'm seeing on Thursday, with the answer on Friday. Sound good?
Back to the program.
This Challenge question just came up in conversation, and without thinking about it too much I thought it might be a good SearchResearch question because (I was thinking) it's in another language / culture, and there's probably no simple, definitive way to answer it. (I was just betting that Wikipedia wouldn't answer it outright.)
But I didn't count on the question being ambiguous. As Ramón first pointed out in the comment stream, there have been lights on the Tower going all the way back to the time it was built. Those were arc lights (which is a lot like the light generated by an electric welding rig--brilliant, dazzling, too much to look at).
I'd just been thinking about the latest installation. As you see in the photograph, there are actually two lighting systems on the Eiffel Tower. There's a rotating beacon that cycles around once every 30 seconds, and then a shimmering set of strobes that fire randomly (those are the little white dots you see on the Tower). You can check out the video below (which I didn't take) to get the effect.
So I guess my question really breaks down into (a) What did Parisians think of ANY lighting scheme, beginning with the first lighting setup from 1889, when the Tower was completed? And (b) When the strobes were added to the Eiffel Tower, how did they react to THAT?
What I did...
I started very much as Rosemary did:
[paris newspaper tour eiffel lights OR lumière ]
That's when I read the Wikipedia article. And THAT's when I found out that it's always had lights... As the Wikipedia article says: "After dark the tower was lit by hundreds of gas lamps and a beacon sending out out three beams of red, white and blue light using two mobile projectors mounted on a circular rail..."
So what I thought was new, was, in fact, as old as the Tower itself. That put a very different spin onto the question!
But it was public reaction that I was interested in. So I thought I'd search for the time when the strobes started up, and also for public reaction when the regular lights began in 1889.
So I tried:
[ public reaction lighting Eiffel Tower ]
(I dropped the lumière part because it had been around so long that I figured it would be covered in English.)
I ended up then thinking that perhaps the FRENCH language version of the Wikipedia page would have something. And while it gave more background (that's NOT in the English version!) on the history of illumination, there wasn't much controversy mentioned.
Learned from http://fr.wikipedia.org/wiki/Tour_Eiffel (in a Google translation):
"As early as 1888, even before its completion, fireworks were fired from the second floor, and even now, it is the place of rendezvous for every Parisian French national holiday .
In 1889, and at first, the lighting of the tower are using 10,000 gaslights , but when the 1900 Universal Exhibition , held in Paris , they make electricity.
In 1925, André Citroën installed a huge advertising light for its brand, ranging in height. Illuminations by 250,000 bulbs in six colors are nine tables, the latter being the name "Citroën" lettering with a stylized version of Art Deco. It remains in place until 1933 that the town has multiplied by six the tax in 1926.
In 1937, for the International Exhibition of Applied Arts, André Granet new lighting designs highlighting the lace structure of the tower."
What this told me was that something as pretty as the strobe lighting wasn't likely to cause much of a fuss for the Parisians. It's been used for fireworks, it's been used as advertising (as Remmij brilliantly found--link to Tower with advertising on it!), it's been through multiple colors, styles, types, and patterns of lights. Twinkling lights probably aren't going to cause anyone to lose much sleep.
Still, I thought it would be worth a try to check out some French newspaper archives. To find a decent list of them, I did a search for:
[ newspaper archive list ]
Yes, I'm under no illusions that Google has ALL the world's news archives (esp. in non-EN-speaking countries).
Luckily, Wikipedia has an outstanding list of links to online archives.
From there, I could pick and choose a couple of archives (e.g., Le Temps, or Le Gaulois, both of which predate the Eiffel). With them, I could do simple searches like
[ "Tour Eiffel" lumière ]
(I double quoted it to be sure I didn't get references to just Eiffel, the architect, and the word lumière as the French word for light, which also includes illumination.)
And you can check out the newspapers from those days (sample search in Le Gaulois).
As we've talked about before, showing the absence of something is often pretty hard. But I read through about 100 pages (50 pages from each of these two newspapers), and didn't find any harsh words about the light. (I did read about how "tablecloths of light fill the fields below the Tower.." and about how such-and-such a worker was injured when a bolt fell several stories and opened up a cut on his wrist during the final stages of construction... but negative press about the illumination? None.
I did pretty much the same procedure for the more recent strobes. Again, nothing.
In desperation, I asked a couple of Parisian friends--"Do YOU remember anything controversial about the strobes when they were introduced?"
They both couldn't remember anything except delight when the new lights came online.
Now, a caution goes here: I'm not a historian of Paris, but my searches into several online resources (including contemporary French newspapers and writings) don't reveal much, if ANY controversy about the lighting. The construction of the entire Tower, yes. But everyone seems to have enjoyed the lighting. Of course, the famous writer Guy de Maupassant often ate lunch in the restaurant at the base of the Eiffel Tower, not because he liked the food, but because it was the only place in Paris he could avoid its otherwise unavoidable profile. 
Search Lessons: There are a couple of lessons here...
First--never assume a question is as simple as your assumptions make it out to be. I would have SWORN this was a simple question when I asked it. I'd foolishly assumed that the installation of the blinky strobes was the first time the Eiffel Tower had been illuminated. When you start a research task... question your assumptions.
Or, at very least, hold on to them very lightly. You might have to give them up, and you don't want to waste a lot of time trying to work yourself out of a lot of assumed ratholes!
Second--Know about the Wikipedia list of newspaper archives. It's a remarkable resource to draw upon, especially for non English-language research challenges.
If this was the kind of question I thought I was going to do a lot, I might well create a Custom Search Engine for the task, and seed it with URLs I found there.
And don't, under any circumstances, do something as foolish as this man, who designed a "coat parachute" and tested it out by leaping from the Eiffel Tower. It looks like a wing suit, but it isn't a wing suit after all. It's just slightly slower way to kill yourself. Check out those assumptions!!!
 Barthes, Roland. The Eiffel Tower and Other Mythologies. (1997) Tr. Howard, Richard. Berkeley: University of California Press.