If you are sure you want a purple Norway maple buy a more recent cultivar with a good purple color. 'Schwedleri' has leaves opening purple and then going nearly green. It is also an old enough name to be used in practice broadly, for more than one introduction so what you may be sold under this name may differ somewhat from what you may read about.

And like most Norway maples it produces a large dense tree tending to end up with bare ground beneath. In my mild zone this cold winter climate species may also become infested with aphids during the dry weather of summer, their secretions making it look as though oiled. Objects and surfaces beneath can be expected to become similarly coated, and may grow sooty mold fungus.

Perhaps the main objection to planting Norway maples in North America is that this is an invasive pest species here, with more than a few sites having becoming flooded with its progeny.

Other commonly offered purple-leaved trees are 'Forest Pansy' redbud, purple European beech, purple-leaved plum and purple-leaved chokecherry. The last has the possible advantage of being a North American native, adapted to continental climates (you don't say what region you are in).

Thank you for your advice. I am in Ontario, Canada...Zone 6. I am looking for a nice maple tree that will give me privacy and shade, however, not take over my yard in 10 years. Our local tree farm has some fairly nice large Shwedler maples I was considering purchasing. I've been doing some research on the trees and am a bit concerned that it may grow too large for my yard.

One in Grimsby, Ontario was 62' tall with a trunk 11' around during 1974.