There seems to be an architectural theme that I see reflected throughout HK's Tomorrowland and that is the use of curves. If you look at the pics the rooflines curve and undulate like waves and there doesn't appear to be any sharp edges or jarring straight lines in any of the main structures.
I could be wrong, but I think this may be due to the feng shui influence we've heard that would be incorporated in HK's park. Sharp lines and straight edges are a no no. I think they're supposed to cause bad luck. I think it might also explain the color palatte used. Warm soothing colors and not the bright neon and sliver/chrome as found in the American parks. Like I said, it's just conjecture on my part, but I wouldn't be surprised if it played some part in it.