Oooh, a blank canvas - and I'm waiting for 'double points' to purchase for the fun-land theme area.

I'd think a down-facing pico over each of the moving "seats" animals (as to eliminate any shadows over riders).  

Some sprinkled controller-driven lights around the upper (and even lower) perimeter, but looking at all those trans-yellow round plate "lights," there's a TON which may not be practical... and could be almost too bright.  From photos, I'm counting ~28 yellow 'lights' on the upper, and ~56 on the lower steps... would be nutty, but in the "real" county fair world, every one of those darn things would be lit -- though at this scale and with 28? gauge wire, and the associated light load, that poses its own challenges of 84+ pico lights.

Surprised they didn't have anything on the top, just to faux light the height of this beauty.  Maybe a pico at the top, by inserting something between the dish and flag pole with a single trans round 1x1 plate?  (Though yes, in that case, I would commit the atrocity of drilling a hole in the dish to pass it through.)

But man oh man, there are oodles of possibilities... and a controller that could "chase" the lights forward with the movement of the carousel, opposite, fast or slow flash patterns a la the ferris wheel, etc.

Rob Klingberg Well, in that case... ;)  

My typical mantra -- being practical -- is thinking in terms of what can be accomplished at a price point not to exceed the set's sell price.  (Leveraging my past example: the wife wanted a fire place gas insert.  Asking price was $3500.  Fine, I'm quite fond of my bride.  Plumbers quoted $4200, $4700, and $1200 to run the gas line for it.  The low quote guy: "I know better than to price out my services more than the product they're supporting."  (He was also the only one to do it as a short point-to-point install, versus wrapping 120+ feet of iron around outside the house; dingbats.)

So if we're going all out: light 'em all, with a controller that creates some movement (maybe upper yellows to sync with the top steps of the platform).  I'm torn on if ALL step / lower should blink in sequence versus perhaps a lower step solid (dimmed?).  Just to minimize a causation of seizures in adorable children.

It's just a ton of lights, like, 100-ish?

As much as I'd be all for other colors, it seems the more classic look for a carousel is all clear (warm white) lighting... or so Google images results for "carousel" are suggesting, a la: 

Awesome perspective -- and cards on the table, I am/was speaking solely from photos.  (I'm holding my cash until double VIP points... selfish, but nearly enough for the next Modular now.) 😉

Man, now that I see the operator red/green... so, we get a motion sensor, and based on the movement of the carousel, have the light correspond (fancy, eh?).  When in motion, green, stopped, red... or vice versa as to what light indicates the available action.  But that's getting zealous.

I'm intrigued with Lisa Sullivan 's suggestion to hit the mirrors.  I can't tell from the photos if there's any real estate at the base of those delicious railing portions to do a hidden "up" light, so one pico vs two, so we'd get the pops of sparkle, but with the obscured hidden light source, it may be more apt to flash with some subtly.

Or if nothing at the base, pop a plate under the gold railing - modified, something like this...?  (I wish I could find all my "neat stuff" parts, as I think this could look even less clunky with a "Plate, Modified 1 x 2 with Clip on Top" (Bricklink pn 92280) with a"LegoPlate, Modified 1 x 2 with Handle on Side - Free Ends" (2540) snapped in and angled upward).