Orange is a relatively unusual color. I've long loved A.p. 'Akane' for its really unique orange-y tones in the spring. Unfortunately, it is not a very vigorous grower: it can easily get scorched in full sun, and regardless of care I (and it seems others on the web) struggle to keep the leaves nice through summer even with shading.
Last year I discovered A.p. 'Coral magic', apparently a dwarf similar to sango kaku. It's not quite the same but it has a very special color as well -- and the good news, this one is vigorous. It can easily take full sun with good health (although if you want nice looking leaves in fall, it might take a bit of extra care).
Finally A.p. 'Orange Dream'. Oddly, the least orange! It does have a color that contrasts nicely with maples that are more green or yellow, but it doesn't exactly shout "orange." This is my first year with this one, though, so I would be interested to see other's thoughts on it.
Last year I discovered A.p. 'Coral magic', apparently a dwarf similar to sango kaku. It's not quite the same but it has a very special color as well -- and the good news, this one is vigorous. It can easily take full sun with good health (although if you want nice looking leaves in fall, it might take a bit of extra care).
Finally A.p. 'Orange Dream'. Oddly, the least orange! It does have a color that contrasts nicely with maples that are more green or yellow, but it doesn't exactly shout "orange." This is my first year with this one, though, so I would be interested to see other's thoughts on it.