Three year old plant has never had any tint of red, rust, orange to it.
Gets partial sun. No color but green in spring or fall. Turns plain tan in winter.

Should I assume it was mislabeled and is the plain green one?

I do have the plain green one and they are identical as far as I can tell.

I recently saw 4" Beni Kazes at a local plant sale and they had red new growth. Mine is 18" across.

I sure don't need two solid green ones. How annoying.