If the new Please Touch Museum at Memorial Hall were a movie, it would be Fantasia. Classically highbrow and totally trippy.

When the idea of moving Philadelphia's cozy children's museum to the neglected 19th-century art palace was proposed four years ago, it seemed counterintuitive, to say the least.

Was the sprawling Beaux-Arts hall, dripping with putti and pilasters, really the sort of place you wanted to unleash a thousand or so sticky-fingered, screaming kids? Children's museums aren't exactly known for their subdued decor. What would the aesthetic mash-up be like once the candy-coated kid's activity center invaded the regal halls of Philadelphia's own Grand Palais, the cherished survivor of the 1876 Centennial Exhibit?

Surprisingly psychedelic. In a good way.

Behind Memorial Hall's freshly scrubbed granite facade and colossal triple-arched entry pavilion there now lies a hallucinogenic world awash in acid green and electric blue, where puffy white clouds joust with Corinthian columns, a cardboard Comcast Tower springs from a subterranean cavern, and a mad Cheshire cat presides over a spiraling rabbit hole, tricked up with funhouse mirrors and trapdoors.

This is Alice-in-Wonderland territory. Big things turn small, small things swell into giants. The exhibits seem to go on without end, with repeated flashbacks to Philadelphia's lost past - Wanamakers, the Pennsylvania Railroad, Lit Bros., Captain Noah. Even adults may be seized with a desire to race through the halls, howling.

The Please Touch's extreme colors and dizzying array of exhibits - or experiences, as museum officials call them - are sure to put some people off. We're used to our neoclassical buildings exuding the serenity of the Philadelphia Museum of Art, whose collection Memorial Hall once housed.

But here, as visitors pass through the arches into the Great Hall, they are immersed in an 80-foot-high parfait of apricot, terra-cotta, black and cream, laced with gold leaf and rosy granite. And those are meant to be the historically correct colors.

When the Please Touch agreed to make Memorial Hall its home, it struck a deal with the city: It promised to restore the central hall of the run-down building to its original grandeur so long as it could have its way with the side wings and the basement, which had been outfitted in the 1950s with a basketball court and swimming pool. Most of the surfaces were painted white over the years, and that is how many Philadelphians think of them.

But there was a Victorian harlot sleeping under that white blanket all the while. As the museum's architects, Kise Straw & Kolodner, led by Philip Scott, chipped away at the layers of paint, they discovered an astonishing carnival of colors, which they have tried to replicate.

Now you segue from walls of pink and mustard in the rear entry hall, to avocado and lemon in the boardroom. If you keep going, you'll soon stumble into a soaring pavilion that has been doused in electric blue from floor to dome.

The extreme dissonance works because the two aesthetics - circa 1876 and 2008 - are really one and the same. The pink and mustard were the Victorian form of psychedelic; the electric blue, acid green and schoolbus yellow are today's pop version. A long, strange journey has come full circle.

It is, by no means, a perfect restoration of the building, which was designed by the Centennial's architect-in-chief, Hermann J. Schwarzmann, and built in an astonishing 18 months. Some colors in the historic rooms seem less than credible. While Kise, Straw was given $44.5 million to restore Memorial Hall, such old buildings are money sponges. That sum made the building functional, but much more needs to be done.

The distinctive glass-and-steel dome, a Philadelphia icon widely visible from the Schuylkill River drives, remains a leaking sieve, its red primer easily seen through the green topcoat. To keep rain from falling on the restored Great Hall, Kise, Straw has covered a protective inner dome with a layer of plastic it calls "the diaper."

While the diaper keeps things dry in the Great Hall, it also muddies the light there. At the same time, the museum was unable to re-create the skylights that once brought the sunshine into the side wings. Nor was it able to repair the zinc garlands that decorate the exterior. By making Memorial Hall a public destination again, the hope is that the Please Touch will grow a constituency willing to pay for those repairs.

The bigger disappointment, however, is the bloated structure built to house the former Woodside Park carousel, attached to the south side of Memorial Hall. Kise, Straw's Victorian-style structure has all the grace of a delivery truck, and its gabled metal roof calls to mind a highway IHOP. It's just not worthy of Memorial Hall. The architects would have done better to contrast the heaviness of Memorial Hall with a light modern enclosure that vanished in the landscape.

Otherwise, Memorial Hall's mix of big and small rooms works perfectly as a children's museum, offering both vast spaces where kids can run wild and cozy corners for quieter pursuits. The grand architecture does for play what it has previously done for the edifying pursuits of culture: It elevates the experience. It could even cause this Please Touch generation to demand better architecture in adulthood.

The wildly imaginative exhibits were all designed by Montreal's Design + Creation, and executed by Michigan's Design Craftsmen. I only wish the pink-and-lavender cafeteria served the drink that made Alice shrink, then I might have fit perfectly into the Wonderland maze, a thrilling contortion of space that may be the best experience in the house. Fortunately, size isn't an issue at the Flying Machine exhibit, where you assemble styrofoam planes and send them soaring on jets of air. The rocket structure is perfectly proportioned to the tall narrow room, and is a work of architecture in its own right.

Don't be surprised if you see some adults elbowing the little ones out of the way.


Contact architecture critic Inga Saffron at 215-854-2213 or isaffron@phillynews.com.