but simplified, and uses the subspecies name "arthemis" in a wider sense than usual.

Much of the red area is usually not considered to be "typical" subspecies arthemis, but is rather ssp. rubrofasciata. "Typical" arthemis occurs primarily within the yellow area and somewhat further north into the red area above the Great Lakes and New England (the area where a majority of Canada's human population lives too). Most of those found further north in eastern Canada (the northern bulk of the east half of the red area on this map) are very similar to ssp. rubrofasciata in appearance.

So. yes the red area is the primary distribution of white-banded types, and the orange and green are the area of those without white bands. "Typical" arthemis is actually intermediate in character between these two basic types, and it's unfortunate that the name was described first for what is basically an interemediate type (but it is also the widespread type over the northeastern US).

All very confusing, but the main point is that red is not synonymous with true arthemis as implied. It would be simpler if all the white-banded types were called by one name as implied here, though it's not currently the usual treatment.

It should also be pointed out that while it is uncommon in the region, the Red-spotted Purple occurs (mostly along riparian corridors), well west into the Plains country as far as Colorado and the Texas Panhandle, and also in the Hill Country of Texas.

That big gap in the west is mostly occupied by Lorquin's Admiral and Weidemeyer's Admiral, which are very close relatives.