Note that there is a warning on the Mini, it is designed for 4 year olds and up...it doesn't come in subtle colors or designs.
The ones designed to fit in the carry-on storage units are the Pro and the Flyer...their wheels are recessed into the chassis
You are correct - the mini does have some "interesting" colors. Out of all of them - this one isn't too bad:
The cheapest I can find the pro is $225 or so, without all the inside stuff. That's too damn expensive - even though it is closer in size to the one I have.